I cut up 6" blocks and had our guest sign them at my daughter's college graduation party. I put out sandpaper glued on to clip boards for people to write on, so the fabric wouldn't slip around. I used fabric pens and then some fine point Sharpies. I had tested by washing over and over the fine point Sharpies on scraps and they did not wash out nor run. In the picture, you can see how I pieced them along with some college memorabilia and some applique. My daughter loved it.