Recently, I had trouble getting IngramSpark to accept cover art for The Nothing Within. They kept sending it back with this error message:
Reason: cover : INK COVERAGE EXCEEDS 300% CMYK ON THE COVER
Solid areas of color on the cover exceed 300% CMYK. This will cause printing problems such as streaking, spotting, and cracking.
This was especially puzzling because the previous week, they accepted the same cover. The cover text had changed in the interim, but nothing had changed about the cover art or its color profile.
Many people working with Print-On-Demand (POD) services have this problem. Unfortunately, though IngramSpark gave a reasonably detailed description of the problem, they offered no advice on resolving it.
Here’s how I worked around the problem. This post assumes you have access to Photoshop (the full version, not Photoshop Elements).
What went wrong?
Large areas of the cover art required too much ink. That might have led to quality problems. Specifically, large area exceeded 300% Total Ink Coverage (TIC), also known as the Total Area Coverage (TAC).
300% ink coverage? What does that even mean?
Most commercial printers create color images with a combination of four inks: cyan, magenta, yellow, and black (CMYK).
If you print something pure yellow, that’s 100% yellow (Y=100). That’s 100% total ink coverage.
If you print something pure green, that’s 100% cyan (C=100) and 100% yellow (Y=100). That’s 200% total ink coverage.
When you make a Photoshop document that uses CMYK colors, by default it uses a color profile that allows for up to 300% ink coverage. That works fine for many commercial presses that print on specially coated paper. But some presses—for example, newspapers and POD services like IngramSpark—have a lower limit.
In IngramSpark’s case, their customer service team shared this with me:
Although our recommended maximum is 240%, we can accept TAC (total area coverage) up to 300% for most cover files, especially if the 300% area is not a large area.
In my case, the problem was caused by large, very dark areas of the cover art.
Why did they accept and then reject the same cover art?
Because human judgement is involved.
Here’s what I’ve learned about IngramSpark’s POD art acceptance process. I’ve learned this not from IngramSpark, but from other articles and blog posts, some of which are linked at the bottom of this post:
- Human review. This isn’t an automated process. A technician does a final review of the cover before printing. (That’s a very good thing.)
- Variability. Different technicians might make different judgement calls. (That’s a less-good thing, but worth it in exchange for human review.)
- Wiggle room. They’re not completely strict about the limits. It might be okay if only small, isolated areas exceed the limit.
- Art type matters. This is mainly an issue for art that has large, flat dark areas. Art with more gradual color changes, like photos and paintings, is allowed to have a 300% limit.
Okay. So how do you fix it?
Every printer, service provider, and cover is different.
Your first option should be to contact your print service provider for technical support.
WARNING: I’m not a printer or CMYK expert. I’m just some guy who doesn’t mind googling and trial-and-error. What worked for me might not work for you.
But having said that—my culprit was the color black.
Um…what? The color black?
The color black.
Let’s say you print something in black like this:
You won’t really get black. You’ll get something more like a dark gray. That’s because the black ink isn’t all that black.
To address this, design programs like Photoshop, Illustrator, and InDesign use something called rich black. Rich black is the black ink with some colored inks added. That makes the black look richer.
Since I’m using Photoshop, I’ll use that for my examples. Here’s Photoshop rich black:
That rich black is (75 + 68 + 67 + 90) = 300% ink coverage. That’s because most design programs begin by assuming you can go to 300% ink coverage.
The actually-colorful parts of my cover were fine. The problem was that my blacks were too black. I needed to use IngramSpark’s rich black:
So just using that version of black in Photoshop will fix it, right?
Because sometimes, layers in photoshop can darken layers below them.
Imagine you have something that’s at exactly 240% ink coverage. Now you layer something on top of that with a drop shadow. The drop shadow—no matter how light it is—will darken the layer below. That means more ink during printing.
Can I just tell Photoshop to limit ink to 240%?
Absolutely, that’s one solution.
- Edit > Convert to Profile
- Destination Space Profile: Custom CMYK
- Ink Colors: SWOP (Coated)
- Change the total ink limit to 240%
But when I did that, some colors got badly desaturated—blue in particular.
Okay. I’m sick of guessing. How do I fix it?
Yeah. I was sick of guessing by this point, too.
The approach that finally worked for me focuses exclusively on black. Specifically, I want to pull those CMYK levels down from Photoshop’s rich black (75/68/67/90), so that they’re no higher than IngramSpark’s rich black (60/40/40/100).
If your image began as an RGB document, you’re ready for the next steps. (You can check at Image > Mode.) But if you began with a CMYK document, it’s best to convert to RGB and then convert back to CMYK. As explained by IngramSpark custom support:
A simple way to ensure that the TAC does not exceed 300% is to convert the final file to RGB and then back to CMYK. This is not ideal for everything, but can work for background images that are more complicated.
So now the whole document should be under 300%. We need to target the large, dark areas to get them to 240%.
First, you need to change the Info pane so that it shows total ink saturation for whatever pixel is under your cursor. To do this:
- Show the Info pane. Window > Info
- Go to its Panel Options. In the upper right corner of the pane, like this:
- Show total ink. Set the Second Color Readout mode to Total Ink and click OK.
- Try it out. Now, wherever you point your cursor, if the document’s color mode is CMYK (see below), the Info pane will show that pixel’s ink coverage. You’ll see the ink level for each of the four colors, as well as the sum of those levels shown as a Sigma on the right, like this:
Now, let’s fix the image.
- Work on a copy. Open your PSD file and save a copy as (name) CMYK.psd
- Merge all layers. Select all layers, then Layer > Merge Layers
- If it’s not already, change the color mode to CMYK. Image > Mode > CMYK
- Prepare to desaturate. Image > Adjustments > Selective Color > Colors: Blacks
Next, fiddle around:
- Move your cursor to the darkest part of the image
- Look at the Info panel; we want to get that Cyan number down to or below 60%
- Pull the Cyan slider a little to the left (try ‑25% to start)
- Put your cursor over that same dark spot again, and check the Cyan level in the Info pane
- Once you get Cyan to be right around 60%, do the same for the other colors: Cyan 60%, Magenta 40%, Yellow 40%—what worked for me was ‑25%, ‑50%, ‑50%
- The image probably looks really pale right now, so increase the Black until you like it (20% for me)
Once it looks good, click OK.
I ended up with an image that wasn’t exactly like the original, but really close—much closer than with the half-dozen other methods I tried.
How can I confirm the image is okay?
Option 1: Submit it to your printing service
If they accept your image, it’s okay. But this option adds turnaround time.
Option 2: Photoshop, one pixel at a time
Use the technique above with the Info pane to check the document. Not every pixel, of course, but spot-check as many problem areas as you can stand to.
Option 3: Actrobat Pro
If you have access to Acrobat Pro, life is way easier.
- From Photoshop, save the document as a PDF
- Open the PDF in Acrobat Pro
- View > Tools > Print Production
- In the right-hand sidebar, click Output Preview
- Near the bottom of the dialog, check Total Area Coverage and enter your target ink value (240 in my case)
- Acrobat shows an awesome map of over-covered areas, highlighted in bright green, like this:
Links to related posts and articles
If that method doesn’t help you, here are some others that might.
- Correcting Common Print Errors — OneBookShelf (2016)
- IngramSpark’s requirement for jackets/covers for POD books — When Clouds Fell (2015)
- Force Color Images to CMYK with a 240% Ink Limit — InDesignSecrets (2014)
- More on Total Ink Limit — New Self-Publishing (2013)
- Reducing the total ink limit in CMYK images using Photoshop — CreativePro (2013)
- Living Within Limits: How to Deal with Lightning Source’s 240% Total Ink Limit — New Self-Publishing (2011)
- Understanding ink limits in Photoshop — The Graphic Mac (2010)
Image credit: Donnie Ray Jones (modified to include CMYK bubble)