8. Color separation. Six colors 12 separations On this page you see six colors or more correctly there are 12 color patches.

Transcription

1 Six colors 12 separations On this page you see six colors or more correctly there are 12 color patches. Each of the six colors are created in two very different color separations. Chromatic Achromatic Chromatic Achromatic Chromatic Achromatic 1. Chromatic separation On the left-hand side the colors are made in chromatic separation created in cmy without using black. 2. Achromatic separation On the right-hand side the colors are made in achromatic separation using black and a maximum of two of the cmy colors. Note: This page is a simulation. See the color separations correctly on the next page. Chromatic Achromatic Chromatic Achromatic Chromatic Achromatic 1

2 R I G H T W R O N G Color settings When viewed using correct color settings the colors are alike. If you look at this via a browser or if your color settings are wrong, the colors might get inaccurate! Alternatively, see the correct colors in Adobe Photoshop (see the next page). To see the colors accurately on your screen, make sure to activate the color settings in Adobe Acrobat to ISO Coated v2 (ECI) or Coated FOGRA39 (ISO :2004). Note! There still might be tiny little differences because of decimals, software versions and screen quality. 2

3 Color 1 L* 82 a* -4 b* 28 Color 2 C 22% M 14% Y 49% C 11% M 7% Y 44% K 12% C 2% M 0% Y 40% K 22% Color 4 L* 58 a* 10 b* -20 Color 5 C 52% M 49% Y 16% C 45% M 43% Y 7% K 15% C 39% M 40% Y 0% K 24% A mix is common sense On this page the six colors are created in three separations. It is amazing that the colors are alike when you look at the very different separations! On the left-hand side the colors are with the chromatic separation. On the right-hand side the colors are with the achromatic separation. L* 69 a* 14 b* 22 Color 3 L* 68 a* 21 b* -5 C 23% M 40% Y 50% C 23% M 47% Y 17% C 9% M 35% Y 43% K 16% C 12% M 43% Y 8% K 13% C 0% M 31% Y 40% K 24% C 1% M 40% Y 0% K 22% The L*a*b* values are the same in all three separations. The L*a*b* values are from the Adobe Photoshop LAB color space and the rendering intent is set to relative colorimetric. L* 72 a* -11 b* -15 Color 6 L* 70 a* -17 b* 12 C 51% M 18% Y 15% C 51% M 18% Y 49% C 45% M 9% Y 7% K 13% C 44% M 8% Y 43% K 15% C 40% M 0% Y 0% K 22% C 39% M 0% Y 40% K 24% On under downloads you can get the files CMYK GUIDE Color 1-6. Open the files in Adobe Photoshop using the embedded profile ISO Coated v2 (ECI) to see the colors accurately. In the middle the colors are from the Triangle Colorscale CMYK GUIDE with a mix of chromatic and achromatic separation. Experience and technical considerations tells that a mix of the separation principles is common sense: Less printing ink is used (Quicker drying time and less set-off) Better gray balance control Less variation through a production More homogeneous colors using different light sources 3

4 C 50% M 20% Y 100% L* 68 a* -19 b* Open the file 19. CMYK GUIDE Separation sample.tif in Photoshop. C 50% M 20% Y 100% 2. Activate the right-hand side of the patch. C 50% M 0% Y 100% C 50% M 0% Y 100% K 20% 4. Add the value (20%) to the black channel. Now the sample is too green and too dark. C 44% M 0% Y 92% K 20% 5. Reduce the green part (c+y) in small steps. Then the sample is closer to your target. C 40% M 0% Y 90% K 20% C 40% M 0% Y 90% K 25% L* 67 a* -21 b* Then look at the Lab values: L* is too dark, a* is too green and b* needs more yellow. C 35% M 0% Y 92% K 27% L* 68 a* -19 b* It is a puzzle to get the sample accurate! When you adjust the color, look first at the color on your screen and then look at the Lab values to create a perfect match. 1% can be the difference between good and perfect! With a little patience you will end up with exactly the same color on your screen and both samples with the same Lab values! Try it yourself on your own screen On under downloads you can get the file 19. CMYK GUIDE Separation sample.tif. Open the file in Adobe Photoshop using the embedded profile ISO Coated v2 and set the rendering intent to relative colorimetric. Adjust the right-hand side to create the same color in two different separations. When you print the samples the colors might not get accurate on the paper! This is because the practical technical world is not always 100% in accordance with the chromatology. So when your job is going to be printed in offset, you should choose colors from samples printed in offset not from a screen view! 3. Cut out the part with the lowest value in cmy (in this sample magenta 20%). 6. Now the sample is too light and you add more black to get closer to the target! Note! There might be tiny little differences because of decimals, software versions and screen quality. With the Triangle Colorscale CMYK GUIDE you have a very fine reference on paper. 4

5 From chromatic to achromatic separation On this page you have 11 samples of six colors, separated in a flow from chromatic to achromatic. On the far left column the six colors are chromatic. On the far right column the colors are achromatic. In between, the colors are a mix between chromatic and achromatic. If you take a traditional cmyk color scale you have a lot of duplicates. For example, the colors on this page will be spread out in several chapters and when it comes to printing considerations who knows which one to choose? In the Triangle Colorscale CMYK GUIDE you will find a color only once with very print proof separations. To see the separation go to the channels in Adobe Acrobat. Use the color picker to read the cmyk values. 5

6 Try it yourself on your ink jet or laser printer Another way of showing the same colors in two separations is to print this and the following six pages in cmyk on your ink jet or laser printer. Cut out the six white squares and move each patch around the respective color plates on the following pages to find the achromatic colors that match best. Six chromatic colors. 6

7 Color plate with achromatic separation without magenta. 7

8 Color plate with achromatic separation without cyan. 8

9 Color plate with achromatic separation without yellow. 9

10 Color plate with achromatic separation without yellow. 10

11 Color plate with achromatic separation without magenta. 11

12 Color plate with achromatic separation without cyan. 12

13 C 65% M 78% Y 100% TVS 243% C 35% M 61% Y 79% K 45% TVS 220% C 100% M 84% Y 60% TVS 244% C 84% M 56% Y 31% K 50% TVS 221% TVS tone value sum The tone value sum (TVS) is the sum of all the cmyk values. On the left-hand side the samples are chromatic without using black. On the right-hand side the samples are with black. C 69% M 100% Y 84% C 33% M 84% Y 51% K 51% C 100% M 73% Y 73% C 83% M 38% Y 48% K 53% The Lab values are the same but the sum of cmyk values are less with the achromatic separation. When you use black you reduce the TVS. TVS 253% TVS 219% TVS 246% TVS 222% In the Triangle Colorscale CMYK GUIDE the TVS is never higher than 300%. C 84% M 100% Y 69% C 58% M 82% Y 36% K 50% C 78% M 65% Y 100% C 54% M 38% Y 79% K 49% TVS 253% TVS 226% TVS 243% TVS 220% 13

14 Separation of picture When it comes to separation of color pictures it is more complicated. If the separation is very chromatic the amount of printing ink is too high and the dark areas are not really dark. If the separation is very achromatic some tertiary color loose their glow and some of the colors can become grainy. The answer is a mix of using the best from both principle and creating an icc-profile. Then you apply the icc-profile to your Photoshop. In general you can use the icc-profiles from ECI, European Color Initiative. Get the files under downloads. Maximum of chromatic separation. Maximum of achromatic separation. Even though the profiles from ECI are de facto you always should confirm with your printing house there might be exceptions! 14

15 Only the tertiary colors It is only in the tertiary colors there is a difference between chromatic and achromatic separation. The primary and the secondary colors. The tertiary colors. 15

16 Black and white in cmyk Black and white pictures separated to cmyk bring you more depth in the tones but it also bring you problems! A black and white picture (in cmyk) only consists of neutral gray tones and therefore it is very sensitive to print variations even inside the tolerances of the ISO standard! Black and white pictures (in cmyk) are also very sensitive to different light sources. See more in 10. CMYK GUIDE Metamerism.pdf on under downloads. The test form shown here consists of the same black and white picture separated with four different profiles. 1. ISO Coated v2 (ECI) 2. ISO Coated v2 300% (ECI) 3. Heavy 4. XHeavy Test form with four different separations. 16

17 The upper part The upper part shows the picture in large size. The lower part The lower part shows the separation forms of the picture. Test form Download the test form 15. CMYK GUIDE TVI test form 1020x720.pdf or 16. CMYK GUIDE TVI test form 720x520.pdf on under downloads. 1. ISO Coated v2 (ECI) 2. ISO Coated v2 300% (ECI) 3. Heavy 4. XHeavy 17

18 1. ISO Coated v2 (ECI) On this and the following three pages the left-hand side of the upper pictures is in black and white. Black and white. Separated to cmyk. The right-hand side of the upper pictures is separated in cmyk. On this page with the ISO Coated v2 (ECI). The left-hand side of the lower sample show the cmy part of the separation. The right-hand side of the lower sample is the black part of the separation. The cmy part of the separation. The black part of the separation. 18

19 2. ISO Coated v2 300% (ECI) This page shows separation with the ISO Coated v2 300% (ECI). Black and white. Separated to cmyk. This icc-profile uses less cmy and a bit more black than ISO Coated v2 (ECI). The cmy part of the separation. The black part of the separation. 19

20 3. Heavy The separation here is created in Photoshop using a lot of GCR gray component removal. Black and white. Separated to cmyk. See more about the gray component in 9. CMYK GUIDE Gray component.pdf on under downloads. Neutral gray and light source The neutral gray colors created with achromatic separation are more homogeneous when viewed using different light sources. The cmy part of the separation. The black part of the separation. See more about this in 10. CMYK GUIDE Metamerism.pdf on under downloads. 20

21 4. XHeavy The separation here is created using very little cmy and a lot of black. Black and white. Separated to cmyk. The cmy part of the separation. The black part of the separation. 21

22 The cmy and the black Here you have the cmy parts (upper) and the black parts (lower) of the four separations. When you go for the heavy achromatic separations you should confirm with your printing house. Maybe they have the right solution for you! 1. ISO Coated v2 (ECI) 2. ISO Coated v2 300% (ECI) 3. Heavy 4. XHeavy 22