Any Color You Like so Long as it's Black

I often get asked about Ink Limits, with respect to coloring comics.

There are two parts to ink limits - Adobe Photoshop Ink Limit settings, and the Ink Limits of the paper the comic is being printed on.

Some papers, like newsprint, are very absorbent. The more a paper can absorb, the less ink coverage, or total ink can be printed on it. Glossy papers hold a halftone dot pattern much better than newsprint, so you put more ink on it. Newsprint or lower grade papers have a lower Ink Limit than glossy papers. This means dark colors can still have greater detail in shadow areas on glossy paper than on newsprint.

Different papers have different Ink Limits. Newsprint generally has an Ink Limit of 240, while glossy comic book covers have an Ink Limit of 300, or even 320 (latter is rare).

What this means is if you are printing on newsprint, no area on the page can have ink percentages that add together to more than 240. Using the eyedropper in Photoshop will give you percentages of C, M, Y, K. Add them together. If they exceed 240, you are over the Ink Limit. This gives you a problem of muddy colors, pages that take longer to dry, and dark colors that can blend into the lineart. And if the paper doesn't dry before the comic is bound and stapled, you end up with pages sticking together, and ripping when you try to open them.

If you color in CMYK, there's no way to enforce ink limits - that is, there's no way to get Adobe Photoshop to limit the total ink in a given area. You have to rely on the information palette and add together the C, M, Y, K totals and make sure you're not going over the Ink Limit for the paper.

In the example below, you have 56C 100M 100Y 13K = which gives you a total ink of 269 - over an Ink Limit of 240.



However, if you color in RGB, you can set up Ink Limits in Adobe Photoshop's Color Settings.

What Adobe Photoshop's Ink Limits do is apply variables when converting from any other color mode (like RGB, or LAB) to CMYK.

There are two parts to Adobe Photoshop's Ink Limits:

Total Ink Limit - the maximum total allowable amount of C + M + Y + K generated when converting to CMYK.

Black Ink Limit = the maximum amount of Black (K-tones) generated when converting to CMYK.

When coloring comics, you want as little K-tones in your colors as possible. Heavy blacks tend to muddy colors, cause fine ink lines to disappear in colors, or even blot out the inks altogether.

To set up your Ink Limits in Adobe Photoshop, open your Color Settings (under the Edit Menu in Photoshop). In the Working Spaces, under CMYK, select U.S. Web Coated (SWOP) v2.




Next, click CMYK in working spaces again, and select "Custom CMYK" at the top of the list (shown below).



Now you'll see a new dialog box. In it, change your settings as shown below:



UCR - Under Color Removal. This replaces colors in neutral areas with Blacks, while GCR replaces blacks in the neutral areas and also in areas of color, and is much more aggressive with adding blacks than UCR.

Dot Gain: 20%
Black Ink Limit: 40% (This is also called BIL)
Total Ink Limit 240% (This is also called TIL)

Of course, you're wondering why the Black Ink Limit is 40% if we don't want K-tones in our colors when we convert the page from RGB to CMYK.

Sometimes you want a little black in areas of dark color. I've found I never get more than 15% K-tones in the darkest areas after converting to CMYK, and almost never have any K-tones in the mid tone colors using this setting.

Some is bound to ask about DC's Ink Limit color settings (100BIL, 240TIL).

Avoid it like the plague, unless you want the absolute worst color conversion possible. I'll show you below. In the image, the original RGB is on the left. On the right is the result after converting to CMYK using DC's settings of 100 BIL and 240 TIL.



Notice in the image above the intense reds and oranges have changed to nice shades of turd brown? Or how about the Purples that have changed to mid-navy blue? Especially how the Cyan to Purple grad in RGB now goes from Cyan to mid-Purple to Navy blue? Even the greens are off.

Now, down below, I've converted the RGB grads to CMYK, using different settings. The Reds, Purples and greens are just as intense and saturated in the CMYK version as they are in the RGB version (RGB on left, CMYK on right). The only thing that's a little off is that the where the Red to Black grad ends at the bottom, the black isn't as solid as I'd like it to be.




Below is the two different CMYK conversions side by side. The one on the left is DC's settings, the one on the right is mine. Quite a difference, isn't it?



Below is an image of just the Black Channel for the CMYK image above. Huge amounts of K-Tones on the conversion using DC's settings in every grad. While there's some K-Tones in the Red to Black grad on the right, it's an acceptable amount. Red is one of the few colors you can add Black to without getting muddy colors, and still keep rich reds showing in print.



So how do you convert from RGB to CMYK, while keeping colors accurate, rich, and K-Tone free? Tune in late Monday for more on Ink Limit Settings and converting from RGB to CMYK.