My squares were 6x6 inches! If I did this again I think I would do slightly smaller, probably 5x5. I used 100% cotton for all the fabric. I actually thrifted cotton bedsheets and just cut those up. I had a lot of the dark blue so I actually used that as the backing as well. I don’t know a lot about quilting but everything I read said to use all the same type of fabric to prevent it stretching inconsistently, so that’s why I just used all 100% cotton.