You would be pretty amused if you could see the looney method I’m using for this comic. It’s definitely and by far the most involved and intuitive process I’ve ever used. Leaving aside the craziness with the vellum, and yes, every panel frame of this comic is a traced credit card, the way I’m doing the color is so nuts that I don’t think it’s transferrable. Basically all the important primaries are done on the vellum with prismacolor markers and then it’s scanned, the contrast is bumped up, and the colors are layed down with color overlay layers set to “multiply.” There are five layers on each panel right now (that may change); two purples, a red (which is terribly close to the purple), a yellow, and a green. Combined together they give this murky, limited palette that helps me to tell the story. The colors are important parts of each characters, and (instead of the usual oversaturated muddle that I draw) spot colors and novelty colors are actually shocking. I like the effect.
Fun fact: I scanned a blank piece of paper in January 2007 and have used it as an overlay layers on literally everything I have done since.