RGB or CMYK: Amazon KDP and IngramSpark
The screen is RGB. Paper sometimes wants a named ink code. In one session you can download both, if they asked for them.
RGB is red-green-blue: that is how a screen paints. CMYK is cyan-magenta-yellow-black: that is how many paper presses print. A Canva green is not the same green in a book. Nobody “fixes” that with an Instagram filter. You convert with a profile: a recipe for how those inks behave on a given stock, in a given region.
Amazon KDP Print, in many authors’ practice and in what the platform has asked for interiors, often wants the PDF in RGB. IngramSpark and offset plants usually name a code: GRACoL (United States, coated or uncoated), FOGRA (Europe: 39, 51, 47, 52, 29 by paper and year), SWOP, Japan Color. We did not invent those names; you pick one because the plant wrote it down. On FormatBookForPrint.com, when you pay the interior session (Path A, B, or C), you can download RGB and each CMYK on that list, one after the next, without closing the tab. If you close it, the session is gone.
Paper leads. Coated GRACoL (magazine, glossy photo) is not the profile for a cream novel interior. Path A paper is cream, white, or heavyweight. Path C has premium colour, white 70, matte or gloss coated. You set paper in specifications and then the colour button that matches what they asked for — not “the one that looks nicer on screen.”
The sample library has colour-test PDFs: type plus one full-page image, in RGB and in each CMYK, to print at home or send to the plant and see how this site converts. They do not replace your printer’s spec; they spare you the surprise.
The jacket is colour too. Path D uses the interior parameters. If Ingram asked for CMYK on the cover and Amazon for RGB, those are two downloads, same as the interior. Do not drop a KDP RGB wrap into an Ingram form that asked for FOGRA.
