Prepress: I do not know the printer, what color profiles should I use?

Question

IMPORTANT: I dont know who the printer is or will be -- the PDF goes to an unknown layout person who will incorporate it in the publication (book). That would make it for offset printing I believe.

Background: I do semi-technical illustrations which are used in publications. I never hear anything once I've sent off the figures -- until I see them in print. Till now these illustrations have only been B/W.

I now want to prepare full-colour PDFs which, I emphasise, will be given to an unknown layout person and printed somewhere unknown. So, I'm wondering should I use no color profile -- or does it matter?

PDF dialog - color output. Preset is "Press Quality" changed to appropriate destination for "European Prepress 2" (see below). I'm using save-as PDF in illustrator (CS4) preserving illustrator editing capabilities.

I am based in Europe, my color settings in illustrator are set to: "Europe prepress 2"

Document color mode is CMYK. All inks are (perecntages of) CMYK.

FWIW I'm self-taught i.e. ignorant of many things I probably should know. TIA for any help!

Answer 1

In this answer I assume you are creating vector graphics and text without images.

In your case, with Color Conversion set to Convert to Destination (Preserve Numbers), the color profile doesn't affect the CMYK numbers you have chosen, so it doesn't matter which profile you choose. You are not using color management, you are kind of "programming" which raster percentages to print "manually".

This is traditionally the way graphic designers have worked for many years and it is a very common way to work (I do it most of the time myself), but it is not really color managed. When choosing the percentages of a color manually it is like choosing a color marker and then use that same marker on any kind of paper. I like that approach because of its simplicity, but the color will look different on different medias.

A way to make use of color management would be to make everything in RGB and then convert to the correct CMYK profile on export. If you have a calibrated ISO certificated screen and use Proof Colors with the correct profile, the colors you see on your screen should (more or less) match a print made by an ISO certificated print house.

But there are downsides to working in all RGB and reasons to work in CMYK instead. The conversion to the correct color profile ensures the best preservation of the colors, but in offset there are other things to look after. For example, thin lines and small text can look blurry if printed with more than one ink, 100% of a color creates a sharp contour, everything below get a (subtle) raggedness from the raster dots. Neutral greys made from all four inks will often get an unwanted color tint. Furthermore, it seems more intuitive for many designers to work with CMYK colors for graphics.

For you, I would recommend the following:

• Work in CMYK if that's what you are most comfortable with. Keep your current settings.

• In "Edit/Preferences", make sure "Appearance of Black" is set to both display and output all blacks accurately.

• In "View/Proof Setup/Customize..." setup like below. Now, once in while turn on "View/Proof Colors" to preview how your colors would look if printed on coated paper ("Coated FOGRA27" is a good standard "guess"). You could try changing the "Device to Simulate" to "Uncoated FOGRA29" to see if your colors looks ok on uncoated paper.

• Since you don't know which kind of paper your illustration is printed on, avoid using colors with too much total ink (C+M+Y+K). For coated paper the limit is approximately 300-320% and for uncoated paper it is approximately 250-280%.