When printing etchings, three felts are generally used. On the top, next to the roller, is the Pusher Blanket (75% wool, 25% nylon.) This felt takes the abuse of the roller and is usually midway in thickness between the other two. To endure the stress, a woven felt is used for this purpose, rather than a pressed felt like the other two. If you were to print with only two felts, the Sizing Catcher and the Forming Blanket would be the ones to choose. It is most economical to purchase precut felts, or order custom felts by the full yard.