The cartoonist at our newspaper hand draws his cartoons, scans them with a flat bed scanner at home and e-mails them to me in the office.
The cartoons have a lot of detail in them and reproduce well as bit maps.
About one a week, however, his editor phones him up in the late afternoon and tells him the cartoon is needed in colour, so he hand colours the already completed cartoon, scans it in as RGB and sends it to me.
Using our normal separation setup, medium GCR/80/240/0 the cartoon reproduces OK except for the black border around it and any type in balloons etc. These tend to be muddy and the numbers indicate it's closer to brown than black.
I've thought of changing the separation setup to maximum GCR and 100% black for the cartoons but tests sent to our proofer are not encouraging.
I'm wondering if anyone has some suggestions.
Regards, John Denniston
John Denniston,
Photo Editor, The Province
Vancouver, BC
john_denniston@bc.sympatico.ca
jdenniston@pacpress.southam.ca
From: J Walton, INTERNET:JWalton@EffectiveGraphics.com
Date: Fri, Oct 27, 2000, 5:42 AM
It sounds like you may have a few things working against you. Are the blacks in the RGB file actually black (0,0,0)? If not, you should correct that before converting.
Also, I don't see how an 80K maximum black is going to help here. If the lines and text are supposed to print solid then I'd recommend they be 100K. I'd be happy to take a look at the RGB file myself, and give a better recommendation after looking at it.
J
jwalton@effectivegraphics.com
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Fri, Oct 27, 2000, 10:31 AM
RE: [ColorTheory] RGB to CMYK cartoons
John Denniston writes,
>>Using our normal separation setup, medium GCR/80/240/0 the cartoon reproduces OK except for the black border around it and any type in balloons etc. These tend to be muddy and the numbers indicate it's closer to brown than black.>>
You are on the right track but a couple of other things have to be done. If you are going to be doing a lot of this you should save all the following as a Photoshop action.
1) (optional) in RGB, open the master RGB curve, take the shadow point and move it toward the center. This will heavy up all colors and type.
2) Filter: Fade (Photoshop 6: Edit: Fade) ModeL Luminosity.
3) Change CMYK Setup to Maximum GCR, 100% Maximum black, just as you have been, and convert to CMYK.
4) Apply Image: Adjust>Selective Color. For each of Red, Green, and Blue, add more of the two dominant inks and subtract almost all the black. This moves compensates for the downside of Maximum GCR, which is that one gets black in bright colors, not a good idea in cartoons.
5) Apply Image: Trap>2 pixels. Trap isn't usually necessary in pictures but here it is because the type will have no CMY in it and the neighboring colors may have no black.
The problem with not using Maximum GCR is, as you have seen, muddy black lines. As long as you compensate for the Maximum GCR as described above, there shouldn't be any hassle.
This is, incidentally, the procedure to use for those needing to reproduce screen grabs for software manuals, etc.
>>I've thought of changing the separation setup to maximum GCR and 100% black for the cartoons but tests sent to our proofer are not encouraging.>>
The question is whether the proofer is truly a CMYK device, or whether it is like many Epson and other printers that take the CMYK input, convert it to RGB and then back to CMYK internally, and then print it. If it is doing that, the type won't look any better on the proof, but it'll be fine on press.
Dan Margulis
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Fri, Oct 27, 2000, 11:17 AM
RE: RE: [ColorTheory] RGB to CMYK cartoons
I will be interested to see if Maximum GCR fixes the black problem. When I have proper ink settings in Photoshop, it converts everything from 5,5,5 RGB on down to something that is definitely black, not muddy, regardless of the amount of GCR. Increasing GCR starts the replacement of color in lower coverage areas as well as the amount; but at the top end (blacks) it doesn't affect the values that much.
I'm thinking the Photoshop is under the impression your black ink is very cyan, and when it creates black, it's creating a build with mostly yellow, magenta, and black, and very little cyan. Either that or it's underestimating the potence of your yellow and magenta ink color (and possibly dot gain as well).
Another factor is registration. If you don't have registration problems, then great. But most newsprinting I've seen has some variation during the run, mostly unavoidable. In that case, using a build for black text is not ideal. So fixing the separation setup alone isn't going to help the registration issue (if you have one). You'll need to trap the text.
Chris Murphy
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Fri, Oct 27, 2000, 2:51 PM
RE: RE: [ColorTheory] RGB to CMYK cartoons
Chris writes,
>>I will be interested to see if Maximum GCR fixes the black problem. When I have proper ink settings in Photoshop, it converts everything from 5,5,5 RGB on down to something that is definitely black, not muddy, regardless of the amount of GCR. Increasing GCR starts the replacement of color in lower coverage areas as well as the amount; but at the top end (blacks) it doesn't affect the values that much.>>
That's correct for UCR, Light GCR, and Medium GCR, and to a lesser extent for Heavy GCR, but Maximum GCR is sui generis. Separating a black that is none too intense in the RGB original using newsprint settings is likely to get you 55c45m45y70k or thereabouts in the first three and maybe 45c35m35y75k if Heavy GCR is used. However, if Maximum GCR is used the result will be around 0c0m0y85k.
In cartoons, the black lines are very thin. Try to print them as a combination of four tints, each at a different screen angle, and they'll be quite blurry. The idea is to transfer *everything* into the black. IOW we don't want to change the proportion of CMY to K, which is the normal objective of GCR, we want to wipe the CMY component out altogether.
Dan Margulis
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Fri, Oct 27, 2000, 3:10 PM
>That's correct for UCR, Light GCR, and Medium GCR, and to a lesser extent >for Heavy GCR, but Maximum GCR is sui generis. Separating a black that is >none too intense in the RGB original using newsprint settings is likely to >get you 55c45m45y70k or thereabouts in the first three and maybe >45c35m35y75k if Heavy GCR is used. However, if Maximum GCR is used the >result will be around 0c0m0y85k.
Interesting - ok well that's good to know.
>In cartoons, the black lines are very thin. Try to print them as a
>combination of four tints, each at a different screen angle, and they'll be
>quite blurry.
Yeah that was my thinking. I was thinking of an easy way to select the parts that you'd want to print black only (text and lines where maybe trapping wouldn't work very well, or just wouldn't apply), and remove that from the original image and paste it into a new document. Convert the original to CMYK, then bring in the copied black only part into the black channel. Then you'd have a good separation, and the areas you want black only would print black only.
*BUT* then your description was a much easier way to achieve that, and therefore easier to script. Who wants to manually do this with every cartoon?
Still, to the original poster, I'd be looking at experimenting with the ink and dot gain settings anyway, because they're probably getting less
than ideal separations (still workable, still acceptable, just not as good as it could be). The muddy black is the reason why I don't think it's an ideal separation table for the actual conditions.
And if they don't feel comfortable with manual tweaking, printing a few patches and having them measured is not as difficult (or expensive) as one might think (solid cyan, magenta, yellow, black, 3-color black, paper white, red, green blue, and 13 steps for each cyan, magenta, yellow and black). So thats 61 patches. And in a bind you could make it even less than that (just don't read as many dot gain values for each ink). The pressman will be happier and so will the color advertisers.
Chris Murphy
From: Hector Antonio Roldan Catalan, INTERNET:impresione@intelnet.net.gt
Date: Fri, Oct 27, 2000, 3:54 PM
Hi, I'm not an expert but here's my idea and why:
WHY
***************
I had the same dilemma on my job, printing cartoons on coated paper and on newspaper. I only use the special separation (black generation, etc) on certain images but I think that we can use something else here:
Using separation metods will affect the look of the image, because it will reduce the gamma for some colors and will expand it for others
So we will have some colors using only CMY values or a low K value and CMY values very high.
Imagine that the cartoon uses a specific color, after separating we will need to fix it.
The metod of a new kind of separation will force us to use some blending. We need only BLACK on the lines and in some other parts of the image, so:
HOW (Photoshop 5)
******************
Working on RGB I will convert the image to CMYK using the settings that work best for printing and for the image, you should know wich to choose
Then, SELECT > COLOR RANGE
1. Here I will use the eyedropper to tell photoshop which color will be converted to a selection (black areas)
2. The most important thing: this will affect other colors so you have to take care of the Fuzzines value
Set the selection preview to White Matte, this will help you to define the look of the desired black plate (I think this is great) This plate won't be definitive, it will be combined with the black we already have. Here you will be able to define a plate that enhance only the lines.
3. When you think you got it click ok and then DESELECT the black channel, now you are working on CMY, with the selection activated press command + x (or ctrl + x on windows) you are CUTTING the selection, now select the black plate again, now you have the CMYK image
4. Now there's the black items you defined have only black ink, I'm sure that some areas don't have enough so: use the litle tab on channels and split them, select the black plate and past the image you have on the clippboard,
5. now you have a new layer, set the options to multipy and flatten.
6. Finally merge the channels and it's done.
(On photoshop 4.0 I used to make the selection, go to cyan, cut, then black, paste and multiply. And so on with the other 2 channels. Doing this on photoshop 5 paste the selection on the selected channel without creating a layer, I don't know why but I tried and sometimes it worked and some others didn't. If anybody knows why send me the tip)
Hector Antonio Roldan Catalan
-----------
impresione@intelnet.net.gt
hectorantonio@intelnet.net.gt
Tel.: (502) 254.04.15
Telefax: (502) 254.02.48
ICQ: 69835949
------------
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Fri, Oct 27, 2000, 7:44 PM
Hector writes,
>>The metod of a new kind of separation will force us to use some blending. We need only BLACK on the lines and in some other parts of the image, so:>>
This is a good philosophy to start,
>>Then, SELECT > COLOR RANGE
1. Here I will use the eyedropper to tell photoshop which color will be converted to a selection (black areas)>>
However, although this method will get the job done, it is a little bit as if I scheduled a flight to Guatemala City with a change of aircraft in Buenos Aires. We would like to avoid making a selection if possible, not just on general principles but because doing it in the way you suggest makes it impossible to reduce the technique to a Photoshop Action. We want an Action, because John tells us that this problem occurs over and over.
The way I suggested will give the best lines, but may cause some color variation. The way you suggest will avoid the color problem but may cause more jagged lines, even though they will be much better than if John had done nothing.
If you would like a more elegantÑand scriptableÑway of doing the same thing:
1. Separate the file in the normal way.
2. Create a duplicate layer.
3. On the duplicate layer, delete the CMY channels altogether. Apply a curve to the black channel that leaves all values 0-50% the same, but increases 75% to 100%.
4. Open Layer Options (PS 6: Blending Options) and set the slider to replace IF black on the current layer > 40%, breaking the sliders apart with the option key so that the transition to the top layer will be smooth.
5. Flatten the image.
6. Apply Image: Trap=2 pixel.
Dan Margulis
From: Clare, INTERNET:clare@typeshop.co.nz
Date: Fri, Oct 27, 2000, 9:49 PM
RE: [ColorTheory] Fixing cartoons
How about asking your artist to send you two versions - the original black and white version and the colour version and you combine them? You wouldn't be able to make an action for this but combining them would be so simple you wouldn't need to.
Clare Strange
TypeShop Ltd
Christchurch
New Zealand
From: Hictor Antonio Roldan Catalan, INTERNET:impresione@intelnet.net.gt
Date: Fri, Oct 27, 2000, 10:31 PM
RE: [ColorTheory] Fixing cartoons II
Dan Margulis writes,
> We would like to avoid making a selection if possible, not
> just on general principles but because doing it in the way you suggest
> makes it impossible to reduce the technique to a Photoshop Action. We want
> an Action, because John tells us that this problem occurs over and over.
It is true, nobody will want to use this kind of fix if cannot be converted to an action
Here's a new idea
1. Separate the file the way you want to
2. Select > Color range (with selection: white matte) and set the area that you want to be only black and adjust it using the preview metod. Click ok (A)
3. Image > Adjust > Selective color. Here on colors select black and with metod = absolute enter 0 for CMY and increase the black to the desired value (B)
4. There's no 4th step, the job is done!
** I created an action and works very well.
A. I suggest this metod to make sure that only the lines will be converted to BLACK ONLY. You will set your options
B. I increased the black amount because sometimes (depending on the settings on step 2) you will have areas with a weak BLACK and we want it to be 100%
Select an image and try it, then set a new action an record these steps. ALL your settings will be saved (Fuzzines value, the values on selective color, etc.)
Hector
From: Steve Smith, INTERNET:colour@dws.uk.com
Date: Wed, Mar 20, 2002, 10:16 AM
RE: [colortheory] Reseparating CMYK
Hello,
I've been lurking for a while and now making my first post. A customer has
supplied some artwork with a shadow value of 63c 100m 100y 100k. Due to
other elements of the artwork the shadow needs to be 0c 0m 0y 100k. The
picture is not a natural picture' it has been composited from several
photos and coloured black and red.
My initial approach was to convert to Lab then redo the CMYK separation.
With a max black GCR separation I got the shadow I needed but the reds get
hammered into oblivion. So I created another separation with light GCR and
layered that over the max black. I then changed the opacity of the top
layer using blend if to knock out the incorrect black.
How would you get from one to the other?
If I haven't explained myself clearly or you would like to see the picture
please say.
Steve
DWS
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Wed, Mar 20, 2002, 4:19 PM
RE: [colortheory] Reseparating CMYK
Steve Smith writes,
>>A customer has supplied some artwork with a shadow value of 63c 100m 100y
100k. Due to other elements of the artwork the shadow needs to be 0c 0m 0y 100k...My initial approach was to convert to Lab then redo the CMYK separation. With a max black GCR separation I got the shadow I needed but the reds get
hammered into oblivion. So I created another separation with light GCR and
layered that over the max black. I then changed the opacity of the top
layer using blend if to knock out the incorrect black.>>
This is the right way to do it in a general sense but there are a couple of
extra steps that aren't really needed.
Here's the way I'd handle it:
1) Make a copy of the original CMYK image.
2) On the copy, run Image: Mode>Convert to Profile>Custom CMYK. Specify
Maximum GCR and click OK to both dialogs.
3) Paste this new version as a layer on top of the original.
4) In Layer: Layer Style>Blending Options>Black move the bottom right
slider about 90% of the way to the left, excluding everything that wasn't
at least 90% black in the original. To assure a smooth transition, split
the slider by clicking on it with Option depressed and move the right half
slightly to the right.
5) Flatten the image and, unless you're sure it's unnecessary, run Image:
Trap because your shadows may now have no ink in common with their
surroundings.
Dan Margulis