From a strictly quilting perspective, I would use ONLY 100% cotton fabric. Any fabric with ANY amount of polyester is much more difficult for the sewing and pressing part of the job. You just want a good quality 100% cotton quilting type fabric. There are many marbly-type solid light colors or batiks that would be great for the autograph blocks. You could even use plain old white muslin. The connecting fabrics should be 100% cotton too. Other people will tell you something different about the type of fabric, but from years of quilting and teaching quilting, I would not consider anything other than cotton.
I hope that is what you meant by the question! If not, try again and I will try to help you again!
Lynda
Yes! That is exactly what I was talking about. I went to Walmart just to see what they had in the fabric section. Not much. Now I will feel better going to fabric store. I hate feeling lost when I go in a store. Thank you!