Sorry, need help ASAP. I designed a book with 20 digital pencil illustrations. I have a hardware calibrated BenQ monitor. Sheridan (the Printer) specifies that for black only printing, all images should be converted to grayscale. Makes sense. They also specify the expected Dot Gain for uncoated stock on a Web Press is 25-27%. Ok cool. However, when I ask about grayscale profiles for 1) converting images to grayscale and 2) soft proofing the images on screen, they just keep answering that no profiles are needed for grayscale. To my knowledge, you cannot convert an image or even view an image without a profile. If a custom one is not selected, Photoshop will use the default profile. Which in my case is Dot Gain 20%. I don't know if I'm thinking about it all wrong, but here are my questions. PS, if you didn't guess yet, I have never printed a book interior in single color black only: What is the best way to convert sRGB illustrations to grayscale for offset web press printing on uncoated stock? I want to prevent the images from darkening too much and losing the fine tone/texture detail in my digital pencil drawings.I tried converting with Dot Gain 20%. It makes the images appear lighter on screen. I tried Dot Gain 25% and it make the images appear darker on screen than the 20% profile. Shouldn't the 25% profile appear lighter on screen than the 20% profile because it is compensating for more dot gain? The on screen effect is the opposite of what I expected.Are Dot Gain profiles even still used in a modern printing workflow? I read on a post here that using just the K channel in CMYK is better for modern workflows.For cover printing, when I asked about color printer profiles Sheridan recommended Coated FOGRA 39. On one of their documents they recommend GRACoL2006_Coated1v2.icc. And on another document for exporting to PDF they recommend U.S. WEB COAT (SWOP) v.2 if the document is not already setup for the correct color space. Are they trying to be confusing or are these profile so similar that it wouldn't matter a whole lot?In the end, I just need to know how to ensure that my illustrations will print nicely on uncoated paper. How can I do this. Is it possible to soft proof for this on screen.

Known Participant

Answered

Converting Images to Grayscale for Print

Forum|Forum|2 months ago
November 8, 2025
5 replies
1125 views

Sorry, need help ASAP. I designed a book with 20 digital pencil illustrations. I have a hardware calibrated BenQ monitor. Sheridan (the Printer) specifies that for black only printing, all images should be converted to grayscale. Makes sense. They also specify the expected Dot Gain for uncoated stock on a Web Press is 25-27%. Ok cool. However, when I ask about grayscale profiles for 1) converting images to grayscale and 2) soft proofing the images on screen, they just keep answering that no profiles are needed for grayscale. To my knowledge, you cannot convert an image or even view an image without a profile. If a custom one is not selected, Photoshop will use the default profile. Which in my case is Dot Gain 20%. I don't know if I'm thinking about it all wrong, but here are my questions. PS, if you didn't guess yet, I have never printed a book interior in single color black only:

What is the best way to convert sRGB illustrations to grayscale for offset web press printing on uncoated stock? I want to prevent the images from darkening too much and losing the fine tone/texture detail in my digital pencil drawings.
I tried converting with Dot Gain 20%. It makes the images appear lighter on screen. I tried Dot Gain 25% and it make the images appear darker on screen than the 20% profile. Shouldn't the 25% profile appear lighter on screen than the 20% profile because it is compensating for more dot gain? The on screen effect is the opposite of what I expected.
Are Dot Gain profiles even still used in a modern printing workflow? I read on a post here that using just the K channel in CMYK is better for modern workflows.
For cover printing, when I asked about color printer profiles Sheridan recommended Coated FOGRA 39. On one of their documents they recommend GRACoL2006_Coated1v2.icc. And on another document for exporting to PDF they recommend U.S. WEB COAT (SWOP) v.2 if the document is not already setup for the correct color space. Are they trying to be confusing or are these profile so similar that it wouldn't matter a whole lot?
In the end, I just need to know how to ensure that my illustrations will print nicely on uncoated paper. How can I do this. Is it possible to soft proof for this on screen.

macOS

Correct answer D Fosse

Dot gain (ink spread in the paper) is built into all CMYK profiles. The dot gain profiles are outdated and not really used anymore. They're not accurate and don't correspond to modern printing processes.

But you need to know which CMYK profile. Keep nagging! You do need it for grayscale, as per above.

Stephen Marsh

Community Expert

They recommend

PSO Uncoated ISO12647_eci.icc

for uncoated:

https://www.sheridan.com/wp-content/uploads/Halftone-Guidelines_ICC-Profiles_Dot-Gain_Dec2023.pdf

M

michaelsgoldmanAuthor

Known Participant

Thank you, I finally saw that too, but I was not sure if it applied because the first parapgrah just talks about scanning haltone images, and my illustrations were made digitally:

"Scanning halftone images for offset printing is a challenging process that requires close attention to detail in order to achieve high-quality files."

The recommended icc profiles would still apply though to converting digital images?

Stephen Marsh

Community Expert

The recommended icc profiles would still apply though to converting digital images?

By @michaelsgoldman

Yes, that's the (presumably emulated) target condition.

Stephen Marsh

Community Expert

@michaelsgoldman - Unfortunately the overwhelming majority of self publishing print on demand service providers appear to be both useless and clueless when it comes to file prep colour management, at least going by the posts from customers such as yourself and looking at their information. Of course, YMMV.

E

ExUSA

Legend

There are going to print a (presumably?) short-run book on a web press? What? That makes no sense.

Stephen Marsh

Community Expert

There are going to print a (presumably?) short-run book on a web press? What? That makes no sense.

By @ExUSA

For an analogue press, no, unless perhaps some sort of gang printing. For a digital web press, perhaps.

E

ExUSA

Legend

I wasn't even going to get into running this through imposition software and creating signatures. Presumably the printer handles that here.

D Fosse

Community Expert

Open Color Settings, and in the Working Gray rolldown, click Load Gray and navigate to the CMYK profile that will be used for print:

If you start with an RGB file, converting to grayscale will now convert to the K component in the CMYK profile, which is what you want. It will also appear as a Convert to Profile option if you have grayscale files in other gray spaces.

InDesign does not have proper grayscale color management support. A grayscale file will just be sent directly and unmanaged to the K channel in CMYK and output on the black plate.

So this is the way to get the correct result. Effectively, since InDesign does not color manage grayscale, you're doing it in Photoshop prior to sending it to InDesign.

M

michaelsgoldmanAuthor

Known Participant

Loading a CMYK profile as the gray space is a great tip. Didn't know you could do that.

I keep asking for a profile though and they have said multiple times that no profile is neede for grayscale. For the cover they mentioned the two in my original post (Fogra 39 and Gracol 2006). Then they have a document that says to output from InDesing to U.S. WEB COAT (SWOP) v.2 if the document is not already setup for the correct color space. But that is for coated paper.

How do I account for Dot Gain if they won't provide a profile for uncoated paper? Also, I would really like to know why the Dot Gain 20% profile looks lighter on screen than the Dot Gain 25% profile.

Thanks!

M

michaelsgoldmanAuthor

Known Participant

Oh and if they won't give you a profile, ask them to provide a press proof for free. Bottom line, profiles are meaningless if the final product is wrong. A press proof is ALWAYS the way to decide if things look right.

Thanks! Press proof was definitely part of the plan. I just find satisfaction in thinking about all the possible variables because I end up learning more than just the answer to my original question. Which I definitely did via this entire thread and all the expert advice thanks to everyone on here 🙂

M

michaelsgoldmanAuthor

Known Participant

Also forgot to mention that I am editing the images in Photoshop. Book layout is in InDesign.

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded