@melinjo: There’s no feature in InDesign for converting artwork to grayscale, like in Illustrator. There’s a plugin from Rorohiko called ‘Color2Gray’ that will convert placed color images to gray. Or, there is a ‘hack’ that will allow you to create a grayscale PDF from any color InDesign layout. See http://indesignsecrets.com/grayscale-pdf-from-a-color-layout.php @es: If what you are looking for is a way to map all the gray tones lighter than a certain gray to white, and all the gray tones darker than a certain gray to black, you could use the Edit >, Edit Colors>, Recolor Artwork command to do this. I tried this in CS4. The .AI vector art looks gray on screen, but the title says ‘Icon.ai’ (CMYK/Preview). It still reproduces as a CMYK file and not Grayscale. I can’t place this into a 2 spot colour document. What to do? Source.