These include switching to an Epson 9880 wide format printer which uses the latest K3 ink set with vivid magenta and light magenta and the use of the Ugra/Fogra Media Wedge v3.0.
Print Engine and Ink Chemistry
All FOGRA Certified proofs and art prints on non-matte papers will now be produced on our new Epson 9880 wide format ink jet. The printer offers the following enhancements over the previous generations of Epson printers:1. Faster printing. The time taken to create each proof is nearly half that of our older printers.
2. Extended gamut using Epson's Vivid Magenta and Vivid Light Magenta inks. Epson's latest ink set can match more than 99% of gamut of the highest quality litho presses. They can also match the majority of spot colours from libraries like Pantone with incredible accuracy.
3. Reduced metamerism. Our retouching and proofs are viewed under controlled lighting conditions but our clients often need to view and approve proofs without access to viewing booths. The new inks produce colours that are less likely to shift under different lighting conditions.
4. Reduced "bronzing". When viewed at an angle Epson's older inks would reflect light and give the appearance of a bronze sitting on the surface of the paper. The new ink chemistry minimises this effect.
Proof Approval & Accuracy
Idea Digital Imaging Ltd are one of the first suppliers of contract proofs in the UK to use version 3.0 of the Ugra/Fogra Media Wedge:
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You'll notice immediately that the familiar colour bars have gained an additional third row of patches.
This means that each proof is now subjected to an additional 24 measurements designed to ensure that it is even more accurate. The added patches comprise:
1. Additional patches at 10% and 20% tint values (columns 4, 5, 9, 10, 14, 15)
2. Additional neutrals made from CMY (columns 1-5 in row 3)
3. Chromatic colour overprints on black (column 22)
4. Richly coloured dark tones (columns 23, 24)
These are really significant enhancements to proof accuracy. Producing an approved FOGRA proof now requires even greater accuracy in highlights, shadows and gray balance -- critical areas if you want to achieve the best results on press.
The increased number of measurements mean that there is more information on the approval sticker. It's important that clients appreciate what the approval sticker means and have an understanding of the values recorded on it.
If your proof doesn't have a sticker then it is NOT a certified proof! Anybody can buy a copy of the Ugra/Fogra Media Wedge or buy software that can place the wedge on their proofs. The presence of the wedge alone is not a guarantee that the proof is accurate.
Approved proofs must be measured with a spectrophotometer. If the measurements are within the tolerances set by Ugra/Fogra a sticker will be attached to the proof showing the measurements, tolerances and other important information about the proof:
The first four lines of the sticker provide information about the printing environment including the ICC profile that is being matched, the printer, software, measurement device and date and time that the measurements were made. You should check that the Reference data is appropriate for your proof -- in this case the proof was a press ad using the ISO Coated v2 (300) profile. It is also worth checking that the date and time of the measurement were made more than ten minutes after the proof was produced so that the ink had time to dry.
The measurements appear below and can be broken down as follows:
1. CMYK primaries: The Cyan, Magenta, Yellow and Black inks are measured for accuracy and the results expressed as dE units (the CIE1976 definition to be precise). Delta-E is a number that represents the distance between the expected colour and the measured colour in the three-dimensional Lab colour space. Delta-E is calculated by adding the differences between the Lab colour values. Our Magenta primary dE can be calculated using a simple AppleScript:
set {L1, a1, b1} to {47.79, 73.73, -2.93}
set {L2, a2, b2} to {48.41, 75.54, -3.88}
set dE to (((L2 - L1)^2)+((a2 - a1)^2)+((b2 - b1)^2))^0.5
set dE to (dE*100 as integer)/100
--> 2.14Technically it is possible for the human eye to detect difference between colour if the dE value is greater than 1 but normally you need to exceed 3 before colours are perceived as different by normal observers. FOGRA approval requires that the CMYK primaries do not exceed 5 dE.
2. Paper white: FOGRA proofs have a distinctive tint that covers the entire page area and the area beneath the media wedge. This tint simulates the colour of the paper used under standard printing conditions. Reproducing this paper white is very important because the papers used in proofing may be much brighter and produce a much brighter highlight than you'd get on press. For that reason the dE tolerance for paper white is much tighter than those used for the CMYK colour values.
3. Max average and Max peak: The last two dE figures are calculated from all of the patches on the media wedge. The Max peak figure reveals the value of the most inaccurate patch on the media wedge. Version 3.0 of the Ugra/Fogra Media Wedge allows a maximum of 6 dE whereas previous versions allowed a maximum of 10 dE.
4. The Hue diff measurements are new to version 3.0 of the Ugra/Fogra Media Wedge. This is a measurement of colour purity which needs to be tightly controlled -- especially in colour values that should be perceived as neutral. You can see that the average gray value is very tightly controlled and must not exceed 1.5dE.
