Converting Images to Grayscale for Print

[michaelsgoldman]

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:

1. 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.
2. 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.
3. 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.
4. 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?
5. 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.

[ExUSA]

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

[Stephen Marsh]

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

By @ExUSA

That's not what I was referring to.

Litho/offset web printing is by definition cost effective for long runs. So I was agreeing that it makes no sense for short runs, unless they have a large print area and can gang up multiple smaller size orders, however, I doubt that this would be economical, even if one  adjusts their expectations of what short run means in this context.

My guess is that this would be a digital web press platform.

[ExUSA]

I wouldn't expect a smaller shop to be able to easily run rollfed jobs because of the cutting involved. Sheetfed is a lot easier for a shop where they don't do big press runs. The whole thing sounds wonky to me though. If its digital then its a modern RIP (I've worked with film-based imagesetters and OLD RIP software that was a joy) but who knows.

[ExUSA]

And I looked at their website and its not a small shop. Hopefully the OP's project turns out ok.

[Stephen Marsh]

@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.

[Stephen Marsh]

They recommend

PSO Uncoated ISO12647_eci.icc

for uncoated:

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

[michaelsgoldman]

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]

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

By @michaelsgoldman

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