Backing paper dissolves quickly when sanding wet but is great for sanding dry. I will use them to clean up my 3D prints. Decent grit selection but definitely not the highest quality. They may have just been in the bag too long and moved around a lot, but some of the sheets had a very uneven texture, especially around the edges. It seems like all the different cereals are there, so that's a plus. Couldn't find anything at my local hardware store with such a wide range in one package at this price. I'm glad I went for 90 pieces because it probably won't last very long.