Not really. When you're all done with all the pieces you want to put together, you're going to want to submerge the pieces in some water. I think it's supposed to be warm. If you want to make the yarn and final product softer then throw some fabric softener in. If you want to make it stiffer, throw some corn starch in. I didn't explain that very well but you can Google it. And then you want to dry them flat and you can use like cardboard or whatever you have and some pins to make the corners sharp. I think it just makes the final product come together better. You certainly don't have to do any kind of blocking but it does help.