umm....I would not want to wash layer cakes at all, I usually do not wash precuts. I may wash a fat quarter but nothing smaller. I really don't like buying precuts in general as they usually are more expensive if you calculate the yardage you are getting. Also not all layer cakes are the same size and you usually do have to some trimming. What is the pattern that you are using, what are the other colors being used in what you are making? If they all are darker colors it may not matter much if there is slight bleeding and you use something like color catchers. Can you snip a small piece off and see if it is colorfast? Not all reds and green bleed. It is a good brand.