some kind of particle board ~ or pressboard,
its usually like a bunch of woodchips (not sawdust like MDF) pressed together with a bunch of glue.
MDF is sawdust pressed together with glue, and is much more dense than the particle board...
much more sturdy imo. dont get them wet though, they soak up water like a thirsty kenyan... and the bloat like a female on her period. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
douse them with a smal dose of epoxy (fiberglass resin) and thatl keep them dry.
why do you need to know?
//edit.
****it. beaten to it. but i was more in-depth //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif