I have been using polyester batting for years to cut my filter pads. I do not like the soft batting in prepackaged roll and prefer the firmer batting cut by the yard from JoAnne Fabric that comes in big rolls in different thicknesses. I always buy the thin 4 oz size as any thicker batting has no additional value once the surface layer got clogged. They can trap very fine particles, but get clogged up quickly and need frequent replacement. So it is better to use in HOBs than canister because it is easy to change filter. I run 3 Penquin 350 in my 125g with big messy cichlid and need to replace one square foot of batting twice a week. The water is polished crystal clear, even 5 min after feeding. JoAnne is always on sale and sells them so cheaply that costs me less than a dime per square ft.
http://www.joann.com/4oz-x-48in-x-4....html#q=polyester+batting+by+the+yard&start=5
http://www.joann.com/4oz-x-48in-x-4....html#q=polyester+batting+by+the+yard&start=5