The Foil that Came in from the Cold Understanding cold foiling as a straight forward technique for brand enhancement White paper
Author: Will Oldham Synopsis When it comes to cold foiling, we avoid it because it s just difficult Said by a printer with 15 years experience Cold foiling is by no means a new technology. Developed in the 1990s for narrow web printing, it was designed to provide a cost- effective alternative to hot stamping foil, specifically for inline processes. When the technology was first introduced it was difficult, and at times unpredictable, as each company developed its own products with little synergy across the component parts. It is the early beginnings of the technique that has caused much of its reputation. However, cold foiling has now matured into a proven printing process. Machinery manufacturers and the substrate, adhesive, ink and foil suppliers have collaborated to ensure all elements work together. As the technology has advanced and the results have become increasingly reliable, rapid growth in cold foil use has followed. Cold foiling has moved on significantly since the early days of long web paths and cationic links. It is now a legitimate and proven process which provides a cost- effective solution for creating brand differentiation. However, the industry perception is still influenced by the output of the early technology. This whitepaper discusses the various elements and the individual requirements of each to demonstrate that cold foiling is now a straight forward technique. It details each stage, consideration and potential pitfalls of cold foiling, and gives a broad understanding of how to achieve the optimum results. These days it s one of the simplest processes in print Said by the same printer with 15 years experience
About API Group API is a leading manufacturer and distributor of foils, laminates and holographic materials, which provide exceptional brand enhancement for consumer goods and printed media worldwide. With roots in the British paper industry, the company s reputation is founded on a trading history going back over a century. Operating from thirteen locations across Europe, America and Asia, API s packaging solutions enable companies across a wide- range of industry sectors, including premium drinks, confectionery, tobacco, perfumery, personal care, cosmetics and healthcare to empower their brands on the shelf and in the hand. Will Oldham, Chief Commercial Officer at API, has been in the graphic industry for 30 years, and has authored this whitepaper, detailing his knowledge about cold foiling and the opportunities they can provide.
Cold foil construction The construction of foil for both web- fed and sheet- fed is the same and is made up of five layers. Cross Section of foil Once applied and the carrier removed, cold foil is two microns thick. In comparison, a hair s breadth is between 40-120 microns. There are now two forms of cold foiling; web- fed and sheet- fed. Both forms require the following three- step process: 1. Print adhesive 2. Apply and nip foil 3. Remove foil carrier For both processes the same basic principles apply: with the correct combination of machinery and component parts, it is a straightforward and economical way of adding eye- catching effects to product packaging.
An overview of cold foiling benefits Inline production Perhaps the most cost and time effective aspect of cold foiling is its ability to be applied inline, meaning that the printing process does not need to be offset, it is simply another printing stage. Shorter set- up times The simplicity and low cost of adapting most UV presses makes this technique easily accessible to printers who would not otherwise invest in expensive hot foiling equipment. Easy registration This reduces set up time and wastage since foiling is not affected by the thermal expansion of dies. The adhesive is printed like an ink and will hold register like an ink, the foil will then only stick to where the adhesive has been printed. Lower die costs Rather than using a brass hot foil die, cold foiling uses a printing plate, which can be up to 98% cheaper. Using a plate reduces cost and gives the customer flexibility to add foil without a premium price. Design benefits The chemistry involved in the manufacture of a cold foil is different from a hot stamping foil, as it relies on a peel- off mechanism, which is purely physical and relies on the attraction and tack of the active components. This means that it allows substrates that would have previously been difficult and even impossible to apply (such as thermal stocks, plastic laminate tubes and heat sensitive flexible packaging) to benefit from decorative foil. A hot foil is designed to have the release and adhesive layers activated by heat and pressure, so heat sensitive substrates can melt and burst. Cold foiling also presents a wide range of creative opportunities as it performs well on fine lines, large area coverage, over printing, half tones and multi- coloured effects. General limitations The advances in cold foil technology, whilst impressive, cannot replace the finish achieved using the traditional hot foil method, especially where uncoated and textured surfaces present particular difficulties for cold foiling. Hot foiling has an advantage on fibrous, textured and absorbent surfaces, thanks to the level of pressure that can be applied during the stamping process, serving to even out and flatten textured surfaces.
Cold foiling is also unable to provide the true mirror shine that hot foiling produces. The metallised layer in cold foil is thinner, due to the need to allow UV energy to pass through the layers of the foil and activate the UV curable adhesives. The results that can be achieved are amazing, from solid areas to fine text Phil Baldwin, Mark Andy
Web- fed cold foiling Cold foiling on web- fed processes is flexible and suits a range of substrates. Being a cold process, it is ideal for heat sensitive materials, such as films and shrink sleeves. It works particularly well on the no label look label that is growing in popularity for products like shampoos and beers. Applications include: Filmic self- adhesive labels Paper self- adhesive labels In- mold labels Shrink sleeve Cartons In the majority of cases, the application of the adhesive is by a flexo process. It can be used in conjunction with the full range of web- fed printing processes, depending on the press used. Typically, the presses will be equipped with UV curing, though there are examples of solvent- based web- fed printing. Typical ink printing processes: Flexo Offset Letterpress Gravure Screen Machinery for web- fed cold foiling The machinery requirements for cold foiling are relatively simple, as it only requires a unit to roll on the foil and roll off the corner. The adhesive itself is applied in one of the printing stations and should be treated as any other print process. The new generation of wider web presses is bridging the gap between labelling and packaging. For example, the Gallus IC5670, a printing press for web- fed flexo printing, can incorporate other printing processes such as carton production, which is traditionally a sheet- fed process. Most print manufacturers now supply cold foil units, either as an integrated part of a new press or as an optional unit, meaning that brand new systems are ready to apply cold foiling and old systems can be retrofitted.
Machinery suppliers with cold foil modules include: Edale Gallus Mark Andy Nilpeter Gidue Omet MPS AB Graphics For a more detailed overview of recommended suppliers please see Appendix 1.
Substrates for web- fed cold foil The substrate is the critical element when choosing the correct foil. For cold foiling, the rule is, the smoother the substrate, the better the results. Film, paper and board are the three key materials suitable for this technique. The properties needed for the processes include print receptivity, a base stock within its shelf life and in general, coated papers are better. All filmic substrates (PE, PP, PET, PVC), are ideal for cold foiling as they are non- porous and prevent the absorption of adhesive. It also allows clean edges and low weight of plastic. The key factors for laydown (appearance) include surface topography, adhesive, weight and chemical affinity. The key factors for adhesion (appearance and performance) include chemical compatibility, UV curing, wetting and chemical/physical bond strength. Conventional coated papers and board are suitable for cold foil printing. Uncoated papers may be successful if they are heavily calendared, not too absorbent and thoroughly tested. It s worth noting that on uncoated surfaces, too much adhesive makes the foil swim, but too little adhesive and there is no foil transfer. Adhesives for web- fed cold foil For web- fed cold foiling only UV adhesives should be used. When working with UV adhesives for cold foil there are many elements to consider, for instance, the type of image area to be foiled, as it could be solid, text, or vignette. If printing onto absorbent stocks, it has to be able to support the design. During the specification process it is also important to consider the following: What is the base stock? Do you have the correct balance of line count vs. depth for optimum release? Is there fine text or dot on the design? Has the anilox been deep cleaned? Is it free from damage?
API foils for web- fed cold foiling TO grade Specialist foil developed with superior UV over- printing capability TA grade A high speed over- printable foil designed to be as versatile as possible across machines and substrates, while delivering the best combination of fine detail and broad area coverage
Sheet- fed cold foil Sheet- fed and web- fed printing is significantly different. The key applications for sheet- fed are web glue labels, commercial print jobs and cartons. The adhesive and ink printing process are offset and both conventional and UV curing adhesives can be used. Typically, the adhesive is applied on the first unit and the foil on the second unit is followed by the ink print units. However, there are machines where the adhesive and foil are applied further down the press. For sheet- fed printing, there is a range of systems either fully integrated or suitable for retrofit. Sheet- fed presses with cold foil modules: Heidelberg (Foilstar) Manrolands (InlineFoiler) Komen Retrofit modules Foil Tone Compact Foilers Eagle Systems/Graphic Art Vinfoil For a more detailed overview of recommended sheet- fed machine manufacturers please see Appendix 2. Substrates for sheet- fed cold foiling Considering the correct substrate, inks, adhesives and foils is crucial to ensure all elements work well together. In all cases, suppliers should advise what the best possible solution is. The most suitable substrates for sheet- fed cold foiling are paper, board and plastics, with an emphasis on paper and board. The smoother the substrate, the better the results, which is why paper and board are ideal materials to work with. It s worth noting that matt plastics should be avoided. Adhesives for sheet- fed Adhesives should have the same print characteristics as ink, with tackiness to enable the foil to stick and transfer from the carrier. It s important to use the minimum amount of glue required, as too much glue leads to scumming and excess foil being applied. However, too little glue leads to an incomplete foil transfer. For sheet- fed applications UV curing & conventional (oxidatively) drying adhesives can be used.
API recommends the following suppliers, though there are a wide range available: Conventional (oxidatively) drying: Saphira (Heidelberg) Printcom (Monrolands) Foiltone Zeller + Gmelin Huber Jänecke & Schneemann Toyo Ink Excessive adhesive could lead to poor print definition or lead to the carrier film breaking, whilst insufficient adhesive application could lead to poor removal of the metallised layer from the carrier film. It is crucial to consider this during the specification process. The adhesives are coloured, facilitating the control of even film weights using a densi- toner. For overprinting, we recommend the UVALUX U7/U73 or UVAFLEX Y7 series. Containers of the UV adhesives should be closed immediately after use and should always be stored in a cool, dark place. The optimum storage temperature is about 20 C, to ensure it is protected from high temperatures and particularly frost. In addition, ensure it is stirred well before using and always clean the printing unit with washing agents. Be aware that the addition of any additive may change the overall characteristic of the adhesive. Cold foils for sheet- fed The key properties for cold foil for sheet- fed are exactly the same as for web- fed. They have a very free release, good bond to adhesive and good receptivity to inks. API foils for sheet- fed cold foiling TU Grade The TU grade is specifically designed for inline cold foiling with UV curing adhesive and inks. It is also suitable for conventional (oxidatively) drying adhesives and inks. Inks It is important to use inks formulated for non- absorbent surfaces, such as films and foils. High- tack ink, for use on plastics and other materials, may need tack to be reduced to minimise foil transfer onto ink printing blankets. Contact your chosen ink supplier for more information. For an overview of recommended ink suppliers please see Appendix 3.
Appendices Appendix 1 API recommends the following web- fed machines, though others are available. Gallus Gallus have a range of machinery from the flexible ECS 340/330, which can expand as your requirements grow; to its ICS 670, a wide web machine for folding carton conversions. Nilpeter Nilpeter cater for a broad range of printing options and is easy to control. The multiple process press incorporates easy load sleeve technology and has an instant set up register, ensuring low waste and reduced set up times. Edale FL- 3 The Edale FL- 3 combined with API Foil s cold gold foil received positive feedback from the trade, in which they reported that they have never seen a better lay down of foil. Douglas Storrie, Edale Appendix 2 API recommends the following sheet- fed machines though others are available. Heidelberg The Heidelberg Foilstar applies foil on 76mm cores and includes single width rolls and multiple slit rolls. It is able to apply large- scale metallic finishes and provides significant cost savings because of its multi- reel operation and indexing. It also does not require metallised paper or board. Manroland InlineFoiler The Manroland InlineFoiler applies foil on 152mm cores for single, wide rolls and on 76mm cores for multiple slit rolls. Foiltone Foiltone is a UK supplier with deep roots in the print industry. The company developed and built the first retrofit cold foil systems in 2006 and provides units for all press makers and sizes. The differential shafts allow customers to run several narrow rolls or one full size roll.
Appendix 3 Recommended ink suppliers: Flint Huber Jänecke & Schneemann Paragon Inks Printcom (Manroland) Saphira (Heidelberg) SICPA Siegwaerk Sun Zeller + Gmelin Appendix 4 Coatings API always recommends using a varnish or lacquer to protect foil and inks from rubbing. Doing so increases resistant properties and provides a high quality finish. For more information, contact your chosen coating supplier. Appendix 5 What the printers say: Windles Group Amazing sheet coverage Ultra fine detail, including reversed out foil areas Flexible colour selection through the use of CMYK palette of inks on foil Multiple colour choice over the sheet. As many colours as you want on one pass Unique metallic imagery Excellent registration No deformation of the material No need for expensive foil dies High- speed foiling
The main factor for ensuring a job runs smoothly is client support. It is important to design with the process in mind. There can be easy mistakes made if mis- handled, both at the design stage and production. But executed well, nothing can beat it. Ian Kear- Bertie, Windles Group MPS Cold foil introduced as product sustainable alternative to other methods Additional option to premium- ise packaging Allows finer detail and increases the finished and effects options Extends capabilities with in- line processes Does not replace hot stamping foil Berkshire Labels Low cost origination The flexibility of producing the origination in- house Full rotary production speeds Ability to foil across multiple presses that we currently have Ability to produce tints, screen, vignettes etc in foil Cold foil is not the answer to everything and there are some substrate incompatibilities but, coupled with our hot foil capabilities, it gives us a very economical and flexible option. Paul Roscoe, MD, Berkshire Label
The Foil that Came in from the Cold API Group Second Avenue Poynton Industrial Estate Stockport SK12 1ND UK +44 (0)1625 650500 www.apigroup.com enquiries@apigroup.com