Proper way to convert sRGB and sGray for print

Bashv

Member
1. Can you tell me, please, what's the proper way of converting sRGB and sGray content for offset printing?

a) Converting sRGB to the CMYK profile required by the printer (let's call it "FOGRA XY") and converting sGray to Dot Gain (10%, 15%, 20%... depending on the printer).

b) Converting both sRGB and sGray to the required CMYK profile, with the difference that the sGray content will be converted to use only the black ink (K) of "FOGRA XY".

2. In case the correct answer is b), what's the proper way to convert sGray to CMYK Black in Acrobat? Should these options be checked: "Preserve Black", "Promote Gray to CMYK Black" and/or "Preserve CMYK Primaries"?

3. Or maybe the correct way is to convert sGray to "Black Ink - FOGRA XY" in Photoshop?

Thanks
 

DYP

Well-known member
Best to ask your printer, as they may want to do the converting on their RIP, especially if they have created an output profile for their press.
 

Bashv

Member
Best to ask your printer, as they may want to do the converting on their RIP, especially if they have created an output profile for their press.

Thank you, @DYP.

I have some color pages in the document, the rest is in grayscale. The printer told me that the colors must be in Fogra52.

When I asked about the grayscale content, they told me Dot Gain 15%, but this sounded more like a recommendation than a rule. I wonder is that a normal practise.

I also don't understand which simulation profile should I rely on when evaluating the gray content: Fogra52 or Dot Gain 15%?

I guess that Fogra's K channel will be used.

Subjectively speaking, the Fogra simulation seems a bit dark, while the Dot Gain 15% simulation looks fine.

Thanks.
 

mrserge

Member
Use K channel from FOGRA52 (PSO Uncoated v3). Most likely printer will use black curve from this standard anyway.
 

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