The local range that I shoot at has the same material that the block uses. It is actually the same stuff, bought from the same company that sells it to the block company. Like many ranges, they used to use cardboard, but it didn't last long at all. They didn't have the man power to keep replacing it. Now that they have the block material, they haven't done anything with it for over a year. The only drawback is that it cost them $10,000 to buy it all. They expect it to last them for more than 10 years, so in the long run, it is much cheaper. And carbons pull hard without a lube.