Edith Cowan University

Transcription

1 Introduction This on line technical manual for Printmakers is specific to the undergraduate Print Media program in the school of Communications and Arts at Edith Cowan University, and for professional and community artists enrolled in the 'Open Bite' Access Print Workshop. The publication supports our studio practice and technical workshops, and offers constant updates in print technology from a number of co- researchers nationally and internationally from within the field. The content is based on the academic and technical requirements of the program and the specific print technology utilised within the studio. The comprehensive text offers back up notes and information for students involved in technical workshops plus related links to researchers, suppliers and artists involved in the practice of Printmaking. The manual covers all the major Printmaking processes. Thanks go to the following people for their contributions and support and for making this publication possible: Amanda Allerding, Print Media technician and co- researcher for her energy and commitment in researching, compiling and publishing this document. The Edith Cowan University Teaching and Learning Committee for financially supporting the project. Austin Bond and Derek Kreckler from the West Australian Academy of Performing Arts for their help and guidance in electronic publishing. Professor Susan Groce, Head of Printmaking at the University of Maine USA for her contribution and commitment to acrylic resist techniques for etching. Keith Howard for his extensive research into non- toxic Printmaking, and Desert Designs WA for their Faculty collaborative of projects with West Australian Indigenous artists. Education and Arts Professor CLIVE BARSTOW, Head of School Communication and Arts PAUL UHLMANN, Co- ordinator of the Print Media Studio and 'Open Bite' Access Print Workshop 2011 updates to document by Vanessa Wallace

2 Health and Safety Health and Safety is a priority in the Visual Arts at SCA. Certain rules must be followed to avoid accidents or causing harm to yourselves or others through improper handling of equipment or chemicals. All people who want to use the print studio must have completed a health and safety induction with the studio staff. The induction is designed to make students familiar with the operating procedures of specific equipment and to create awareness of the safety facilities within the studio. In the Print Media studio there is a risk management system in place designed to minimise potential risk of harm or injury by both equipment and chemicals. The user of the studio has a responsibility to abide by the rules and particular instructions set by the studio. The risk management system begins with general verbal instructions on health and safety backed up by this handout. Any new user to the print studio is required to sign an induction sheet and then do a refresher induction every 6 months. When any new material or process is introduced, accompanying safety information will be given. You should expect this and ask before proceeding to use anything you are not sure about. Where hazardous equipment and chemicals are located there are both standard operating procedures adjacent as well as protective equipment such as gloves and goggles. You must abide by the safety operating procedures. There are Manufacturers Safety Data Sheets (MSDS) that deal with the hazardous properties of particular substances located in a file in both etching and screen- printing rooms which would be useful for you to familiarise Faculty with. of Health and safety is high on the agenda of art schools world- wide as the potential health hazards Education of many materials used in art practice has been and Arts under scrutiny since occupational health and safety regulations became an industry standard. Non- Toxic printmaking has evolved since the late 80's as a consequence of associated health hazards and is committed to finding alternative lesser toxic materials to use in art practice with an emphasis on materials that emit vapours. Screen- printing etching and photo- etching are the first three printmaking processes to employ non solvent based materials at Print Media C+CA. Water- based inks have been used since 1992 in screen- printing. Oil- based inks used for intaglio and relief printing are free of lead. Lesser toxic materials are being explored and experimented by the print media staff in order to provide a safe working environment, however, there is a need to use acids and solvents for some processes and by following the safety instructions provided, the risk of injury is completely minimised. There are three ways that toxins can enter the body, through respiration or inhalation, ingestion, or through skin absorption. It is much easier to control toxins entering the body via the mouth or through the skin and so a concentrated effort is being made to eliminate the risks of airborne toxins, by ensuring adequate extraction is in place, or by substituting those materials that produce vapours for those that don't.

3 Nitric acid, solvents and oil- based grounds are the offending substances that are used in the print studio that would be dangerous, in degrees, if taken in through the respiratory system over a long term. Extraction is used to remove the airborne vapours from the studio environment and so the risk is minimal providing students use the offending materials under extraction and with awareness. All students using the studio need to become aware of accident prevention as well as the correct procedure for handling an accident as a duty of care to yourself and others. Induction process for students and staff Print Media studio Conditional to working in the print studio is a thorough induction of the work practices in the area with emphasis on health and safety. This must take place during the first class meeting of each semester and at the introduction to each new material or process. 1. Students and staff must be informed of all the general rules of the studio both verbally and in hard copy before they can commence any work. The studio user must sign an induction form and studio staff sign off as the user is n=inducted into each piece of equipment. 2. A tour of the studio must take place with a studio staff member with a view to familiarizing with studio safety operations, eg: Locating Personal Protective Equipment PPE's; Observing the signage and Standard Operating Procedures SOP's; Locating Exit points and emergency procedures; Locating Extraction Fans. Locating Safety shower and eyewash; Locating of the MSDS file. Understanding a MSDS. 3. The initial use and teaching of all equipment and particular processes must be accompanied by the relevant health and safety information Faculty pertaining of to that practice with re emphasis on PPE's and SOP's and reference to chemicals Education and the MSDS information. and Arts IN THE ETCHING ROOM; Handling steel correctly, PPE's Using the guillotine, observing the guards Using the paper guillotine and cutter Using the acid bath, about acid, extraction, PPE's Using solvents and bitumen under extraction, about solvents, PPE's Using the hot plate, about grounds and fumes Using the orbital sander, PPE s Using the press Hygiene About Inks IN THE SCREEN PRINT AND UV EXPOSURE ROOM; Using the UV exposure unit, PPE s Using photographic chemicals, PPE's and extraction Using screen wash chemicals, PPE's Using the High Pressure hose, PPE's

4 Terminology Additive colour is represented in the RGB colour model as red, green and blue light that when added together create other colours and when viewed in equal intensity display white. Analog is the name for data represented as a continuous waveform Aquatint (as referred in this manual) is a process where a fine dot is sprayed onto a metal plate as a ground to produce tonal effects Assembled Plate is a plate assembled from parts onto a single backing plate or assembled on the press bed. Bit is the smallest part of computer data represented by the absence or presence of electrical charge, 1 (present), 0(absent) Bitmap A bitmap describes the relationship between pixels as units that store elements of data and how they are displayed on screen. Burnisher is a tool used in etching to force fine lines together by its action. Byte a byte is a set of eight bits of computer data allowing 256 combinations of strings Carborundum is silica grit that is used to prepare the surface of lithographic stones. It can also be used as a material on a collagraph plate where it will produce rich blacks from its inked surface. Chine colle (Chinese collage) is a collage technique where lightweight coloured papers are laminated to the support paper in order to add colour to the work. Tissue and rice papers are most suitable. Collograph is a type of plate that is made by building a textured surface off the baseboard. Collograph is so called because it is an extension of collage. Continuous tone images use the film grain to create Faculty the of illusion of gradated tone. Digital data in the form of discrete values. Most Education digital data representations use the binary number system. and Arts Editioning is the process of printing a determined number of multiple prints from one plate. Embossing is a way of creating a raised surface on a support, usually paper. Plates that have a high raised surface such as collagraph plates are used to emboss. Engraving To incise the surface of metal, wood or other material. Etching is a process using acid to bite below the plate surface to produce an intaglio plate for printing. DPI or dots per inch that an output device such as a monitor or printer can produce. Dry point is a direct method of engraving a plate, metal or plastic are two possibilities. Acid is bypassed with drypoint and the technique produces softer lines than etching. Frame the basic unit of information in Quick Time movies, film and video. Ground is the term given to various substance that are used to coat and provide an acid resistant surface on metal plate. Halftone is a process where a continuous tone image such as a photograph is simulated through a mechanical screen made up of a dot pattern. The screen translates the tones into dots of varying sizes creating a visual effect of tones. A halftone screen can also be produced digitally. Intaglio is a term that encompasses certain techniques such as drypoint, etching, hard ground/soft ground, sugarlift, photo engraving, and the method of inking is to push ink into the recesses of the plate and wipe it from the raised surface. The plate is then rolled through an etching press with damp paper on top. The loosened fibres of the paper allow it to be moulded into the inked recesses of the plate so that the ink can be transferred to the paper. Lino Printing is a relief print where the image has been inscised and cut away from a lino block.

5 LPI lines per inch describes the resolution of a halftone screen that is measured by the number of dots counted over a linear inch. LPI x 2 = DPI. Mezzotint is a process of first building a rich plate surface by using a mezzotint rocker back and forth over the plate to build up a dense cross pattern of dry marks that when printed black would produce a rich black print. Burnishing tools and steel wool are then used to remove or close the marks. It is a way of working from dark to light. Monoprinting is a way of printing 'unique' single print editions. Offset Printing is a process of transferring an image from one plate to a second from an intermediatory surface. Pixel is a picture element used to describe bitmapped graphics. Process Colour refers to three colours cyan, magenta and yellow with black. Proofing is the process of printing, trialing a plate, with a view to continue to make changes to a plate before it is editioned. Registration is a system of mark making that allows precise alignment for overprinting. Relief Print is a print that has been printed from the raised surface of a plate by rolling the surface with ink. Screenprint _ serigraphy is a process where ink is forced through the open areas of a silkscreen onto a surface. Stencil a stencil is either a positive or negative mask that can be made from a variety of materials, that will allow either the positive or negative aspect of the image to be printed. Substrate is the 'surface beneath', in printing refers to the surface being printed on, could be paper, glass, wood, metalé Subtractive colour is based on two sets of primaries Education cyan, magenta and yellow that when printed on top of one another in various dot patterns form and red Arts green and blue. Vector based graphic is a system of storing information about graphics as geometric and mathematical coordinates. Wood Engraving is a relief print on the end grain of a block of wood. Wood Cut is a relief print from the length of a piece of wood.

6 Etching Traditional and non toxic print processes will be covered in this section. Intaglio platemaking involves making a recessed image from a plate's surface so that when the plate is inked it transfers from the lines and marks in the plate as a positive image. It is the method of inking, taking an ink impression from below the surface of the plate that gives a print the distinction of 'intaglio'. Engraving and Etching are two methods encompassing various techniques to produce marks on a metal surface. Acid is used to bite the surface of a metal plate to create an image. Drypoint, Line Engraving and Mezzotint are all non- acid methods of intaglio plate making. Drypoint requires the use of a sharp tool to engrave the surface of the plate. A soft metal such as zinc brass or copper is most suitable to work with or a drypoint can be used on a plastic polyethylene sheet. Drypoint produces lines and marks that have a characteristic soft edge. As the drypoint needle scratches the plate it furrows and throws up a ridge that gives the line a soft and distinctive quality when it is printed. A burr can be thrown up on one or both sides of the line depending on the angle of the cut. The best tools for drypoint are diamond or sapphire tipped needles or a less expensive carbide tipped steel needle. Dentist tools and steel scribes may be suitable if they create a burr. A tool with flat sides would channel a line without throwing up a burr. The angle of the needle as it engraves will produce different burrs and get lines that vary in intensity and colour when printed. A needle held almost vertically will create a line with a dark centre and soft sides. When the needle is held at an angle it will throw up a burr on the opposite side. Faculty It is worth of experimenting with power tools for drypoint. A Dremmel is an engraving tool that has Education many attachments useful for mark making upon softmetals and plastic. The burr will eventually wear and Arts down from the pressure of the press and so a limited number of prints can be printed from a drypoint plate. Safety in the etching studio The acid room at SCA has a reasonably powerful fume extractor that removes the vapours associated with nitric acid (normally used with steel or zinc). Gloves, goggles and plastic aprons are provided and required when working in the acid room. An eye wash spray and safety shower is located adjacent to the acid bath. Acid can cause serious burns if splashed on the skin or if fumes are inhaled. Wash any acid solution from your skin with copious amounts of water for a minimum of 15 minutes and always seek medical attention. Do not lean into the acid booth. Wash acid from plates with water in bath next to acid bath then follow with a second rinse in sink provide after they are removed from the bath. Ferric Chloride does not give off gas but is extremely corrosive and skin contact must be avoided. Wash with running water any Ferric Chloride that contacts your skin for a minimum of 15 minutes and always seek medical attention. Caustic solution will also burn if splashed on skin. Use running water to rinse. Solvents can irritate the body's mucous membranes and so it is recommended that they be used in the clean up room, which also has fume extraction. Protect your skin from solvents with barrier cream and /or gloves.

7 Solvents that must be used in the clean up room are turpentine, thinners, meths, eucalyptus oil and shellac. Handle large sheets of steel with heavy cotton gloves provided. Always hold from the top never from the sides. Always inform a studio staff member if there is an accident. Etching Etching is a process whereby areas of a metal plate are covered with an acid resistant ground and the plate is then immersed in an acid or mordant solution. The areas that have no resistant ground are eaten away or corroded by the acid. An image is etched into the metal plate that then has an upper surface and a recessed surface. The plate can be inked either intaglio or relief to transfer the image to paper. Steel, copper and zinc are three often used metals that can be used for etching. Steel is the hardest of the three metals and it is also the cheapest. It is produced from iron and carbon and lesser amounts of manganese, silicon, sulphur and phosphorous. Steel has an oily and slightly textured surface that prints a light grey tone unless the plate is well ground and polished. Because steel is so hard aquatints and lines will not wear down after printing. When steel is exposed to nitric acid a gas is produced and so nitric acid should always be used with extraction. Lines have a tendency to bite out or widen as the acid etches. Colour will not be affected when printed from steel. Steel will rust once degreasing has weakened its oily coating. Coat steel with vegetable oil or bitumen during storage. Copper is a base metal but small amounts of other Education materials added increases its hardness. The crystalline structure of copper is four times finer and than Arts zinc, giving its surface an even texture, making copper most suitable for fine detailed work in etching and soft ground as well as direct processes such as dry point and engraving. It will wipe back cleanly after inking and will not alter colour except for a reaction with vermillion. Fine lines etched in copper with Ferric Chloride will bite deeply and retain their quality. Copper can be etched in Ferric Chloride or Nitric acid. It is very expensive to use. Zinc contains small amounts of cadmium, lead and iron. It is a softer metal than steel and so can be used for drypoint. Its surface is smooth and it doesn t hold plate tone. A zinc plate can be wiped back to a very clean surface that enables clean contrasts to be produced between the incised and flat areas of the image. The chemistry of zinc can affect some colours particularly yellows which will print towards green and whites and pinks toward grey. Separate acid or mordant baths are necessary for etching the different metals. Copper must not be placed in a bath used for Zinc or Steel. Preparation of steel plate Once a plate is cut to size it is necessary to file and bevel the edges so the press blanket is not damaged during printing. Bevel the edges to a 45 degree angle. It is optional to buff the surface of the plate with a grinder. Steel has a lot of impurities within and a textured surface that means steel will print with a tone even before etching. Buffing a steel plate will produce a polished surface that removes the tooth of the plate, so that the plate can be wiped back to a very clean surface.

8 Degrease the plate, ammonia and whiting powder are available in the studio but Ajax will also do the job. Mix the ammonia and whiting to a paste on the plate while it is in the trough. Rub all over the plate and rinse well. Dry immediately as steel will oxidise fairly quickly if damp. The back of the plate will need to be coated with acid resist ground, either bitumen or shellac. Covering the back with contact will also be a suitable, less toxic acid resist The plate does not need to be backed before it is worked on, only before it is immersed in the acid bath. It can be a disadvantage to back a plate that will be heated on the hotplate as the acid resist backing will soften and cause the newspaper beneath it on the hotplate, to stick to the back. Preparation of zinc and copper plate Edges need to be bevelled on all metal plates that will be rolled through a press with a blanket. Zinc and copper have smooth surfaces and it is necessary to give the surface a tooth so that the ground to be applied will adhere well. Use a fine 360 sandpaper pad on the orbital sander to rough the surface of copper and zinc. Degrease with whiting and ammonia, or Ajax, rinse and dry thoroughly, taking care not to handle the top surface. Copper has a tendency to oxidise quickly from moisture so degreased plates need to be kept wrapped in paper towel to avoid moisture and oil from handling. Adhere contact to the back of the plate as an acid resist. Autographic & photographic mark making The principle of etching is acid resist. A ground Education is a substance used to mask certain areas of the plate to resist the acid that the plate is immersed in. There and Arts are different grounds and ways of applying grounds to create areas of resist. There are different ways to expose the metal to acid after ground has been applied so that tone and texture can be created. The next section will cover bitumen grounds and acrylic grounds. Bitumen Grounds; There are four categories of grounds; hardground, softground, liftground and washes. Bitumin grounds work well with all metals. Bitumen grounds are oil based and will adhere to a metal surface quite easily. They will need to be removed from the plate with a solvent such as turpentine. When they are heated during application they do emit airborne solvent particles and the user needs to be aware. Hard ground provides a resilient surface to work with. It will not easily chip or mark unless it is taken to with a tool. Traditional hard grounds are asphaltum or bitumen preparations. There are various tools that are made for scribing metal plates for etching but 3 inch nails, dental tools, steel wool, and other inventive means will work to remove the ground to create an image. It is unnecessary to scratch the metal itself, the aim is to remove the ground and let the acid etch the plate. Hard Ball Ground is a hard ground preparation made from bitumen and wax. It provides a transparent ground when it is applied and so is particularly useful for repeat applications of ground after an initial biting because the plate surface can be seen. It is not as hard as the liquid bitumen preparation and

9 will eventually foul bite if left in the nitric acid for a long time. A hardground roller is set aside for hardground use only and it is important not to use it for other grounds. Lay the prepared metal plate on a sheet of newspaper and heat it on the hotplate. Rub the ballground over the plate surface and roll out evenly with the hard ground roller. The wax in the preparation softens to allow the ground to cover. Remove the plate is from the hotplate and continue to roll as the ground cools and hardens. The plate will have an even transparent cover and should be quite hard. There are various methods to expose the metal underneath. The ground can be scratched with a sharp tool, a nail, wire brush or any inventive other way. All these marks would be positive marks, they will etch in the acid bath and will be marks that will hold ink and print. It is not necessary to engrave the metal beneath the ground. Wax crayons also resist acid and so a soft drawn line can be made with crayon as a negative. The ball ground could be used as a crayon to draw marks that will resist the acid. A photographic image can be transferred to a metal plate from a silkscreen with water based bitumen paint as an acid resist material. This is one method of transferring photographic images to metal plate for etching as a negative. If you want to develop a positive this can be done by inverting the image on photoshop before printing and exposing it on a screen. To prepare the screen and develop an image onto the screen, see the section on photographic stencils in screen printing. Education Prepare a metal plate taking extra care to file away and any Arts sharp edges and degrease well. Clamp the screen in place onto a silkscreen baseboard and register the screen over the plate. When the screen and the plate are aligned, secure the plate with double sided tape to the base board. Tape strips of thin straw board around the plate to hold it in a secure position. Tabs can be placed under the corners of the screen to hold it off the baseboard. This gives the screen 'snap' and helps prevent the screen mesh sticking to the plate. Select a hard squeegee with a square edge to pull the ink across the screen in one pass only. It is important to use a squeegee that is wide enough to pass over the plate once. Place a thin line of ink along the top edge of the image on the screen and screed the ink over the plate. Lift the screen and allow the inked plate to dry. Water based bitumen dries quickly on the screen and will need to be washed off immediately following transfer to the plate. Remove screen from baseboard and take to the outside wash area. Spray the front and back of the screen with screen wash and then gentle scrub the screen with a clean brush. Use the low- pressure hose to completely wash out any bitumen. Next spray the screen with detergent on both sides and then wash with the low- pressure hose. Soft ball ground provides a flexible surface that can be impressed and so is useful for creating texture on a plate surface. The soft ground preparation used in the print studio is a bitumen and wax mixture that has a greater percentage of wax than the hard ground. A roller is set aside for softground use only and it is important not to mix the soft and hard ground rollers.

10 Heat a plate on the hotplate and dab the softground ball on the plate until it softens easily. Use the soft ground roller to roll it evenly over the plate surface. Remove the plate from heat and let the plate cool slightly. The ground will roll evenly if it is rolled while the plate is cooling. Soft ground is sensitive enough to pick up fingerprints or the veins of a leaf. The grounded plate can be drawn on through a sheet of paper, which would produce a softer line than one scratched through a hard ground or it could be run through the press with textured material that would lift the ground exposing the metal. As textured material is impressed in the ground, it lifts the ground from the plate and leaves the metal exposed. A plate that has been rolled with soft ground should be impressed fairly quickly as the softness of the wax in the ground and its ability to pick up texture is dependent on temperature. A plate that has been stored with soft ground may not impress as well. Handle the plate carefully as the ground will scratch easily. Sandpaper Aquatint can add tone and texture to a plate surface. Roll a plate with hardball or soft ball ground and place sandpaper face down to meet the ground and roll through the press. Experiment with different grade sandpapers for finer and coarser marks. Immerse in the acid bath for a short time. This method attempts to imitate traditional resin aquatint along with mechanical half tone screens. Lift grounds work on the principal that oil and water don t mix as do many other printmaking processes. The positive image is laid down with a water- based medium and rolled over with an oil based ground that acts as the acid resist, or negative Faculty image. of The water- based medium is then washed out or lifted, exposing the plate surface and leaving Education the oil based ground intact. Metal plates, particularly steel must be well degreased before and applying Arts a lift ground or the ground wont adhere to the surface of the plate. Sugarlift is a saturated sugar / water solution that enables a painterly positive image to be made on the plate. Apply Sugarlift with a brush. Allow to dry (this may take several hours depending on the thickness of the application). Putting the plate on the hotplate at very low temperature can speed up the drying time but if too warm the sugar in the solution will crystalise. The sun will speed drying time. When the liftground is dry to touch put the plate on the hotplate at a low temperature and roll hard ground carefully over the entire plate surface. Remove the plate from the heat and cool, then rinse under cold running water. The sugarlift will dissolve to expose the previously painted area. Back the plate and then etch. Because fairly wide marks can be made with a brush with the sugarlift method, wide areas of metal will be exposed to the acid during biting. Wide openly bitten areas do not always print dark tones during printing, they have a tendency to wipe out in the centre but collect ink around the edge creating a line. Applying an Aquatint would help to create dark tones in openly bitten areas that would easily wipe out during inking and wiping. Condensed milk can be used as a lift- ground medium to screen- print an image onto a metal plate. This is the same principal as the sugar lift only the method of application for the lift ground is different. Because condensed milk has a high- saturated sugar content, it has a similar effect to traditional sugar

11 lift grounds. This is another method of transferring photographic images to metal plate for etching as a positive. To prepare the screen and develop an image onto the screen, see the section on photographic stencils in screen- printing. Prepare a metal plate taking extra care to file away any sharp edges and degrease well. Clamp the screen in place onto a silkscreen baseboard and register the screen over the plate. When the screen and the plate are aligned, secure the plate with double- sided tape to the base board. Tape strips of thin straw board around the plate to hold it in a secure position. Tabs can be placed under the corners of the screen to hold it off the baseboard. This gives the screen 'snap' and helps prevent the screen mesh sticking to the plate. Select a hard squeegee with a square edge to pull the ink across the screen in one pass only. It is important to use a squeegee that is wide enough to pass over the plate once. Place a thin line of condensed milk along the top edge of the image on the screen and screed the ink over the plate. Lift the screen and allow the printed plate to dry. Lift the screen and allow the milk to dry, about 30 minutes. When the milk is dry put the plate on low heat on the hot plate and apply a hard ball ground over the entire surface. When the ground has cooled and is set, run the plate under cold water and rub the milk off the plate. Coat the back of the plate with shellac or contact and put in the acid bath. It is important to remember that the back of a plate needs to be protected from the acid either by painting with bitumen or shellac or covering with Faculty contact. of Education For more detailed information on non toxic etching and processes Arts Visit Keith Howard's Non Toxic printmaking site. Open Bite; Large tonal areas can be created by open biting a metal plate, exposing a large area of the plate to the acid. Typically an open bite will print an edge around the open area and may wipe out in the middle. Aquatint works well with large open bite areas as it creates a tooth in the plate surface that will hold more ink during printing. Stopping Out. A plate can be worked and reworked by stopping out. Bitumen or shellac is applied over certain areas of the plate that have already been 'bitten' to preserve their tone and the plate can be put back in the acid bath to re bite other areas. This enables tone to be controlled with acid. Contact or wax crayon could also be used to mask out areas. Corrections and alterations can be made to remove scratches or lightly bitten lines using different tools. A burnisher is a tool that can polish the surface in small areas of the plate. It can remove scratches if is used with a little oil to force the sides of a line together so it can not hold ink. With a little linseed oil on the belly of the burnisher use a forefinger and apply pressure on the hook of the burnisher to the surface of the plate. Burnish in small circles to avoid adding unwanted lines to the plate. A scraper is used on its broadside to scrape away deeper lines. The scraper is scraped across the plate in different directions so powdered metal is produced obliterating unwanted marks and scratches in

12 the plate surface. The resulting marks may then need to be burnished. The scraper and the burnisher are used together to rework areas. Acids and mordants Nitric Acid is used for etching steel at WASOVA. Adequate ventilation in the form of fume extraction is a must when using nitric acid. Steel immersed in Nitric Acid produces Hydrogen gas as it bites; Copper immersed in Nitric will produce nitrogen dioxide gas. The gas is given off in bubbles that can be brushed off with a feather as they appear and congregate on the surface of the plate. The action of the acid removes some ground on either side of the line that can produce a line that is broad and deep. The Acid heats up as it bites and eventually exhausts itself. The greater the surface area of metal that is exposed in the acid will cause the temperature of the acid to rise and speed up the etching process. Nitric acid is diluted with water in the bath, usually 6 : 1 which is a moderate to weak strength. Greater control of the etching process can be achieved with a weaker solution of acid. A strong solution would cause fast biting good for deep biting or strong line work whereas the weaker solution would etch aquatints and fine lines with greater precision. Ferric Chloride is an alternative mordant to nitric acid that does not release gas. Ferric Chloride is a saturated solution of corrosive salt crystals that Education will bite more deeply and less broadly than nitric acid which means fine work will have less tendency to and undercut. Arts As Ferric Chloride etches, sediment from the metal collects and remains in the lines. The sediment will impede the clean biting process unless the plate is lifted from the mordant, rinsed and replaced. For this reason plates bitten in Ferric Chloride are usually placed upside down to allow the sediment to drop to the bottom of the acid bath. Edinburgh Etch is Ferric Chloride with citric acid. The addition of citric acid speeds the etching time and aids the biting of clean fine lines as the citric acid acts to remove sediment from the lines as they etch. Ferric Chloride and Edinborough etch can be mixed in a vertical tank that has a small aerator, like a fish tank pump, to circulate the solution aiding the removal of sediment from lines in the metal. Inks and inking Etching, relief and lithographic oil- based inks are made up of pigment in a linseed oil base with various driers and binders added. They all vary in consistency and viscosity according to their particular application and quality of make. Etching ink is used for intaglio printing. Etching inks are generally rich in pigment with a butter like consistency that ensures the application and removal from the plate surface is not too difficult. It has a thinner consistency than relief ink so that it can be wiped back more easily. It can be thickened up with calcium carbonate (whiting) to be used for relief printing if necessary. Relief ink is stiff ink with a tacky consistency when it is rolled out. Relief inks are quite stiff in

13 comparison and are made to suit being rolled out to a thin cover. They are often transparent (depending on the particular colour) holding less pigment than etching ink. Process colours commonly used in commercial printing industry are relief inks. It can be thinned with linseed oil for use as intaglio ink or as a medium to be applied with a brush in a monotype. Inking An etched plate can be inked intaglio or relief or both. Inking intaglio requires etching ink that has less viscosity than relief ink, it contains more oil and is easier to wipe back than relief ink. Soak paper prior to inking the plate. To ink an Intaglio plate make sure you have a scrupulously clean surface to prepare the ink. Using a spatula remove a wedge of ink from the tin. The ink is best removed from the tin as a wedge from a pie, to reduce the surface area of the ink in the tin that will skin once it has been opened. Take a minute to turn the ink on the slab to warm it and also to expose any small lumps of skin that will need to be removed. The ink can be applied to a plate with a rubber or plastic scraper on its broadside ensuring ink is pushed into the recesses of the plate. Once the plate is entirely inked, the ink on the upper surface of the plate needs to be wiped back. Several materials can be used for wiping back. Tarlatan is stiff open weave gauze with starch sizing. It will remove ink swiftly from the plate surface with proper use. Take a piece of tarlatan and wrap it into a ball. With a vigorous circular motion rub it evenly over the plate surface until the top plate surface is revealed. If the plate has large areas that are openly Faculty bit of to proceed with the tarlatan may wipe out ink from the open areas. A plate etched with deeply Education bitten lines would not be at risk. Paper wiped flatly across the surface will finish removing ink from and the top Arts of the plate Muslin will allow more sensitive control of tone on the surface of the plate, however it is soft and will lift out ink from the recesses of the plate. Wrap a strip of muslin around a rag ball to use. Tarlatan, yellow paper from a phone book or scrap cartridge can be used for wiping. Colour etching There are several ways to approach colour etching, a plate can be inked intaglio with more than one colour, or can be inked both intaglio and relief, ink can be painted onto the plate and colour added by collaging coloured papers in a method called chine colle. Stencils can be made to define areas of colour. Several plates, each inked with different colour, can be printed over one another. Colour will mix when forced together under pressure if wet but will overprint if dry. To ink intaglio with colour it is important to keep colours clean and separate. Colour can be applied to sections of the plate and wiped back carefully. Linseed oil can be mixed with ink and painted on with a brush. Relief Rolling Cut a wedge of ink from the tin and turn it over for a minute to warm the ink and reveal any lumps of skin which can be removed. Select a hard roller that is as close to the size of the plate or wider than the plate.

14 Roll out a slab of stiff relief ink. Make sure the slab you will roll the ink out on is absolutely clean. Small particles of old dry ink are easily picked up on a roller and transferred to the print. Roll the ink into a thin pad so that it does not squelch. Roll the plate surface with few rolls to avoid lifting ink out of the lines and contaminating the colours. Colour can be added by relief roll to a plate through a stencil. A separate stencil is made for each colour. To make a stencil, trace or mark the shape from the plate. Use a blade to cut it out. Position the plate on the table and register it with tape along two sides. Position and hinge the stencil over the plate. Several stencils can be hinged over the plate. Use a soft roller to roll the ink. Chine Colle is a collage technique using coloured paper, generally fine paper such as tissue or Japanese papers, to add colour to a print. The type of paper to be collaged should be lighter than the support paper. A mixture of clag and water beaten to remove lumps can be lightly brushed over the tissue alternatively clag clear gum glue can be used. If the glue is too thick it will bleed through the tissue. Place the glued paper onto the plate on the press bed glue side up. Place the support paper down and run through the press. Multi- plate colour etching When printing multiple plates to produce overprinted colour, it is preferable to etch the final printing plate deeper than the succesive plates. This allows Faculty a heavier of deposit of ink on the key drawing plate and avoids ink rejection from previous printings. Education If more than one plate is to be printed a method and of registration Arts is necessary. Multi- plate colour etching offers many possibilities in terms of the variety of colours that can be made and the ways those colours are applied to the plates. Place a sheet of newsprint on the press bed. Lay the clean plate on the newsprint and trace around it. Remove the plate. Place the sheet of paper that will be printed over the plate and register it with tape. Remove it and place a sheet of acetate over the newsprint. It is important to consider that the paper to be printed needs to remain caught under the roller after the first plate has been printed. The paper needs to be long enough and positioned close enough to the roller that it can stay under the roller while the first plate is exchanged for the second plate. Acetate is used because it can be wiped between plates to keep the press bed clean and its transparency allows the register marks to be seen. Care of studio equipment About the presses SCA print studio houses seven presses that suit different plates and methods of printing. The two Albions are hundred year old Platen type presses that apply pressure from above in a stamping action upon the inked relief block. One is used for printing relief block printing, the other is set for letterpress to be in use for semester 2 in 2012.

15 Small wood and lino blocks are best printed on the Albion press. To manage the pressure, the block is packed between sheets of card beneath it and paper on top of it that can be added or removed as needed. The block sits ink up on the packing, sandwiched between the bed and the tympan that covers the block and paper before it is pressed. The Albion has a 5cm deep bed that allows quite thick blocks such as woodblock to be printed. Five flatbed presses of varying size are used for both relief and intaglio printing of metal plate and collograph plates. The flatbed press has an upper and a lower roller that are chain driven. A heavy gauge metal bed is sandwiched between the rollers. Felt blankets sit between the plate and the upper roller to protect the roller and to aid even pressure over the printed surface. Setting the flatbed press; the press must be set so that equal pressure is on both sides of the roller. Both sides of the press should be tightened (and loosened) simultaneously including the largest press. Never overtighten the press. Plates of different thickness will require the press to be set for the particular plate. To set the press, ease the pressure off the rollers and run a plate through the press with dampened paper. If the paper has an even emboss from the edge of the plate and the bed rolled through without strenuous effort, then there is probably enough pressure set. Apply a little more pressure and repeat if the paper did not emboss well. If at any time it becomes quite difficult to turn the press as it mounts a plate then don t proceed. Stop immediately, reverse the action and release tension off the press. Protecting the blanket The blankets we use at WASOVA are felts. They Education are easily impressed and cut by sharp objects that have been rolled through the press under too much and Arts pressure. All metal plates need to have their edges bevelled. Metal or hard plastic objects must never be rolled through the press (if in doubt please speak to studio staff) and collograph plates require a special blanket between the felt and the plate. Care of the rollers The rollers we are using in the print studio are compressed rubber rollers. To deposit ink evenly across a surface they need to be clean and free of nicks, dents and dried bits of ink. When a roller is not in use it should be resting on its carriage or in the rack off its rubber surface. To clean ink from the roller, vegetable oil followed by detergent can be used with a rag. Alternately the roller can be washed in the parts washer tank. It is important to be thorough. Offsetting Offsetting is a method of printing from one surface to a second surface and then transferring that print to a third surface so that a 'right way around' copy of the first surface is reproduced on the third. By offsetting, several plates can be produced with exactly the same image that can then be worked individually but may be printed on one surface eventually, in register. A plate is inked and placed on the press bed. Register the plate's position with tape. Thick mounting tape is best as each plate can be fitted snugly into a taped corner.

16 A large sheet of paper is placed over the inked plate with enough overhang to remain caught under the press roller as the plate is rolled through. Replace the inked plate with a prepared plate that is exactly the same size as the first, lower the printed paper and roll back through the press. The paper acts as an intermediatery and what results is a second plate with a replica image of the first. The image on the second plate serves as a guide to the first and can of course be worked in different ways. The second plate does not need to be the same material as the first. A print from an etched steel plate can be offset to cardboard if wanted. The first plate will probably need to be re inked and the paper replaced for subsequent prints. Education and Arts

17 Collograph The collagraph is a relief plate that is made building textured surfaces onto a backplate. The back plate could be cardboard, metal, wood or plastic. The materials that build the textured surface could be glue, carborundum, hessian, string, foil, modelling paste, sandpaperéthe possibilities are endless. Whatever material is used needs to be able to withstand the pressure of the press and also not damage the press. Metal and hard plastic objects or objects that sit more than.5mm in relief will damage the blanket on the press. The height or thickness of the material that is adhered to the backplate needs to be considered. If there are several varying heights of raised surface on a collagraph plate the back plate surface wont print as much detail as the higher relief parts of the plate. The back plate can be inscised although if detail from both below and above the surface of the plate is to be printed then the height of the plate needs to be quite low to the back plate. The press must be set properly for the height of a relief plate as a thin guage press bed can be warped by rolling a plate through the press under too much pressure. Preparation of the collagraph plate: Select a backing plate and materials to build a surface on the plate. File the edges of plastic and stiff card. Different adhesives are necessary for different surfaces. Aquadhere glue will work well with wood and cardboard surfaces. Acrylic Gesso and Binder medium are very good Faculty adhesives of on a cardboard surface. The binder needs to be flexible, waterproof and resistant to the solvents Education used for cleaning. If it is necessary to run two glued surfaces together and through Arts the press, a sheet of plastic must be used between the plate and the felt to protect the felt blanket from glue oozing from the plate. Different surfaces will print in a variety of ways and materials have a language of their own. A heavy carborundum collagraph will have an entirely different resonance to a collagraph made from fabrics and aluminium foil and ink will behave differently on surfaces. Some materials that may be worth experimenting with are; Aquadhere glue on strawboard, This glue dries with a clear smooth surface and ink will wipe off it easily creating white lines or marks on an image (printed on white paper). If the glue is scraped over a cardboard surface it can be combed and manipulated to a degree as it is setting. The addition of a little plaster or whiting will stiffen the mixture so that it will hold textures and marks. Plaster itself will crack under pressure but mixed with glue and gesso will be a more flexible surface. Gel medium can be added for greater flexibility. If scraping this mix over the entire surface of a plate it may be necessary to build a retaining wall from wood or plasticine depending on the size of the plate. The mix should not coat the plate thickly,.5mm is enough. You will need to work the mixture quickly as it begins to set as soon as it is spread. Carborundum is a black abrasive grit that when sprinkled over glue becomes a rich textured surface to print from. Carborundum comes in grades of coarseness, from 80 _ 240. The coarser grade (80) will hold more ink and produce denser colours at printing than the finer grade (160+). The glue that holds the carborundum to the plate can be applied by brush or scraped on to a surface and textured, and with the addition of carborundum will produce strong and dense marks. It can be interesting to work

18 glue alone and glue with carborundum on the same plate. The foundation, that is the glue, can be laid down in a similar way but the carborundum will hold a lot of ink whereas the glue will reject it. Shellac or aquadhere can be applied over the surface of a carborundum mark to seal it and reduce the amount of ink that will print from the mark. Cardboard or matboard can be torn, cut and incised before being glued to a baseplate. Matboard will slice with a blade to produce fine lines. Once the plate is made it will need to dry and harden overnight if aquadhere glue or resin has been used. If the back plate is strawboard or card both sides need to be painted with shellac, one the glue is fully dry, so that the subsequent inking and cleaning wont destroy the surface. The shellac needs to be left overnight to dry. Printing Although the collagraph is essentially a relief plate, the printing process is the same as for etching. This enables the ink to be withdrawn from both incised marks and from relief surfaces, As the collagraph is physically high compared to etching plates, the plate needs to be printed on damp paper. Pre soaking the paper loosens the fibres in the paper to give the paper flexibility to mould into and pick up as much textured information from the plate as possible. Rag paper is suitable for collograph and so are other sturdy papers such as Guarro and stonehenge. Soak paper well before rolling out the ink. Ink can be applied by rolling the surface_relief; or using a tooth brush or nail brush to rub the ink into the surface and then wiping back_intaglio, or a combination. Use the appropriate ink for the application. Education and Arts