UNDERSTANDING THE COLOR CHARACTERIZATION PROCESS FOR TEXTILE PRINTING. Jonathan Read 2017

Transcription

1 UNDERSTANDING THE COLOR CHARACTERIZATION PROCESS FOR TEXTILE PRINTING Jonathan Read 2017

2 UNDERSTANDING THE COLOR CHARACTERIZATION PROCESS FOR TEXTILE PRINTING ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Output ICC profiles are built upon a myriad of variables and predetermined condi8ons. These variables & condi8ons are the building blocks or founda8on for the quality & accuracy of the final output. If the founda8on is poorly built or altered a@er the ICC profile is created, then the ICC profile may be rendered useless and predictable color reproduc8on is impossible. The key to success is consistently controlling variables. Primary Ink Restrictions RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

3 ENVIRONMENTAL FACTORS ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Temperature Primary Ink Restrictions Humidity Electrical (Amperage, Voltage, & Ground) Static Electricity Dust, Dirt, & Debris RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

4 ENVIRONMENTAL FACTORS Temperature, Humidity, Electrical, & Debris Optimum Conditions: 68 F (+/- 10) & 50% RH (+/-10) Affects: -Ink absorption on printed substrates -Droplet placement & jetting Symptoms: -Ink bleed & coalescence -Paper cockle -Clogged Nozzles -Banding -Ink color/density shifts -Ink voids on printed substrate -Bad dot patterns

5 MEDIA TO PRINTER CALIBRATION ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Media Loading & Take-Up Unit Procedure Linearization Printhead Height Primary Ink Restrictions Printhead Alignment (Uni/Bi-Directional) Media Feed Adjustment Heat Settings RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

6 MEDIA TO PRINTER CALIBRATION Media & Take-Up Unit Loading, Printhead Height, Printhead Alignment, Media Feed Adjustment, On-Printer Heat Settings Affects: -Droplet placement, jetting, fixation Symptoms: -Fuzzy, blurry, grainy appearance -Bad dot pattern -Banding

7 OPTIMIZING HEAT PRESS / CALENDAR ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Temperature Primary Ink Restrictions Dwell Time RIP Settings Pressure Placement Ink Bloom Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

8 Ink Bloom: Comparing different dwell times on heater: 10 sec. 20 sec. 30 sec. 40 sec. 50 sec.

9 OPTIMIZING HEAT PRESS / CALENDAR Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Affects: -Color gamut -Ink consumption -Consistency Symptoms: -Dull / flat color -Excess ink left on transfer paper -Color change -Non-uniformity across media width

10 RIP SETTINGS & DEVICE OPTIONS Halftone / Dither Settings ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Resolution Primary Ink Restrictions Printhead Pass Count RIP Settings Overprint or Second Strike Variable Dot Setting Light Ink Transitions Print-head Voltage & Waveforms Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

11 RIP SETTINGS & DEVICE OPTIONS Halftone/Dither, Resolution, Pass Count, Overprint/Second Strike, Variable Dot, Light Ink Transitions Affects: -Print Speed -Overall print quality -Resolving power -Color gamut -Droplet placement -Ink consumption Symptoms: -Low productivity -Bad dot pattern -Fuzzy, blurry, grainy appearance -Banding -Color fidelity -Over-inking artifacts -Low total ink limit

12 PRIMARY INK RESTRICTIONS ICC Profile T.A.C. Cyan, Magenta, Yellow, Black, Light Inks, Spot Colors, & Device N Colors (Total Ink Limit) (Total Area Coverage) Linearization Each channel can expense up to 100% of ink. Primary Ink Restrictions In most cases 100% is unnecessary & some ink restriction is required to allow for re-linearization. RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

13 PRIMARY INK RESTRICTIONS Primary Ink Restrictions Affects: -Color gamut -Color accuracy Symptoms: -Dull/Flat Color -Hue Shift -Heavy ink consumption -Fuzzy, blurry, grainy appearance -Over-inking artifacts -Banding -Low total ink limit

14 PRIMARY INK RESTRICTIONS Demonstrates how primary ink restrictions provide the framework for the device s color gamut.

15 LINEARIZATION Linearization is the process of determining the default tonal response of a device and altering it s response to a desired & repeatable state. The unaltered tonal response of a device is usually nonlinear (an increase in ink dispersion doesn t produce an equal increase in density). By calibrating the tonal response to known and repeatable state, you can re-linearize back to that state when the tonality drifts over time. ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Primary Ink Restrictions RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

16 LINEARIZATION Unaltered tonal response of the black channel. Desired response

17 LINEARIZATION Linearization Affects: -Smoothness of gradients -Tonal detail -Ink consumption -Gray balance / Neutrality Symptoms: -Loss of shadow or highlight detail -Lack of consistency -Hue shift -Possible heavy ink consumption

18 TOTAL INK LIMIT Limits the maximum total amount of ink that can be used when mixing primary inks (C,M,Y,K). Each channel can expense up to 100% of ink x the amount of ink channels = 400% The goal is to set the maximum total ink consumption to the highest acceptable level without producing over-inking artifacts. ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) Linearization Primary Ink Restrictions RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

19 TOTAL INK LIMIT Example of a test target used to determine the maximum level of total ink to be used.

20 TOTAL INK LIMIT

21 TOTAL INK LIMIT Examples of Over-Inking Artifacts

22 TOTAL INK LIMIT Examples of Over-Inking Artifacts It can be very difficult to determine over-inking artifacts on dye sub transfer paper. Sometimes it helps to look at the paper after it has been transferred to see what has remained. The most important thing is the end result, the finished transferred product. It that looks good then it doesn t really matter what is occurring on the paper. Before Transfer / After Transfer Before Transfer / After Transfer

23 TOTAL INK LIMIT Total Ink Limit Affects: -Color Gamut -Gradients -Tonal detail -Ink consumption -Gray balance / Neutrality Symptoms: -Over-inking artifacts -Loss of shadow or highlight detail -Lack of consistency -Hue shift -Possible heavy ink consumption

24 OUTPUT ICC PROFILE ICC Profile T.A.C. (Total Ink Limit) (Total Area Coverage) The ICC Profile describes the color gamut that can be achieved based upon all of the previous conditions. They are used to translate the appearance of color from one device to another device. ICC Profiles do not correct over-inking or bad print quality! Linearization Primary Ink Restrictions RIP Settings Dot Pattern, Resolution, Pass Count, Print Speed, Overprint/ 2nd Strike, Variable Dot Settings, Light Ink Transitions, etc. Optimizing Heat Press / Calendar Temperature, Dwell Time, Pressure, Placement, Ink Bloom, etc. Calibrating Media to Printer Head Height, Nozzles, Uni/Bi Directional Alignment, Media Feed Adjustment, Heat/Cure Settings, etc. Ambient / Environmental Conditions Temperature, Humidity, Static Electricity, Bad Grounding of Equipment, Dust/Dirt, etc.

25 ICC PROFILE The ICC Profile in created by printing a range of various colors, measuring them, then creating a characterization dataset. The IT8.7.4 Target is a Print Industry Standard Target for CMYK Printer Characterization. It consists of 1,617 Patches IT8.7/4-2005

26 ICC PROFILE GCR (Gray Component Replacement) & Black Generation When the characterization data is brought into a ICC Profiling Engine you can decide how you want to produce black when generating the ICC Profile. 100% GCR is a way to replace component gray (CMY) with single channel black (K). The overall effect is ink savings without compromising the achievable color gamut. Another benefit of using a high amount of GCR is to minimize metamerism. K % Black Start Amount of GCR 0% Lightness

27 ICC PROFILE GCR (Gray Component Replacement) & Black Generation Special care should be taken when deciding the level of CGR to use and where to Start black replacement. If your single channel black ink produces a very grainy appearance and you start black too early, you may see peppering or black dots in areas that aren t desired like skin-tones. *Look at your linearization target to see how grainy your K ink is to make an educated guess as to where to start black replacement. K Start in Highlights K Start in 1/4 Tones K Start in Mid-tones K Start in 3/4 Tones

28 ICC PROFILE & GCR (Gray Component Replacement) Affects: -Color Accuracy -Gray balance / Neutrality Symptoms: -Metamerism -Heavy/light ink consumption $$$ -Ink consumption

29 Jonathan Read 2017 ICC PROFILE