I've used 3"x6" strips of the diamond lapping film (6, 3, and 1 micron)for about a dozen razors. Seems to still be working just fine. Before, I was able to get razors shave-ready off stones in a trial and error, hit and miss fashion. However, my experience with diamond lapping film is that it is very forgiving. I just hone away the scratch marks and it always seems to give a good result. I wet the surface with soapy water. My main gripe is I can't keep the film from sliding around on the glass. I haven't tried doing the paper cushion trick yet.