The working difference with RGB vs CMYK modes in Photoshop.

When I started working on my graphic novel called “reMIND“, I read that printers needed CMYK files so I decided to create all my Photoshop pages in CMYK only. I worked in this mode for years thinking it was similar to RGB but just printer safe. I Ignored the fact that some of the filters didn’t work because I rarely used them. A few years in, I was trying to adjust my pencil lines to be solid black with Levels but could only get a light gray line for whatever reason even though there was solid black elsewhere on my canvas. There was no real reason for this and it drove me nuts when it happened. I mean, printers can print black so what’s the problem here, CMYK?

I switched over some of the problematic files to RGB and easily got the lines to turn black. Then I switched it back to CMYK and it finally looked right. I started running into other problems adjusting the Hue/Saturation of specific colors in my CMYK files. Sometimes I’d try to adjust the saturation and my textures would disappear. Sometimes when adjusting a color, I couldn’t even get it into the right hue. Or when I’d try to turn the brightness down to black it would turn lighter. I worked around these problems before but now I was starting to get frustrated. I switched my file to RGB again and suddenly after years of denial my eyes were opened.