My success rate with CMYK seems to only be about 20%... So I decided to try use a different technique to draw Yoshi.

This time round, I was using fine point sharipe's. I took an image of Yoshi (that I had done previously in an early B&W test), and masked off all the major colours in the image: Yellow, red, orange, green, blue and black.. I ended up with one image mask per colour, and then draw it on (in no particular order) an A2 page. Because I was largely using exclusive masks, I didn't have any colours bleed into each other.

I think this will work well for cartoon style images, where you have a colour marker to each colour on the image.