Natural materials mattered to us, as we didn't want to be sleeping on foam, made from chemicals and leaching toxins. This mattress is very thick, is firm and comfortable, and very very warm. Noticeably so! We use a mattress protector with it, an approximately 1cm thick soft wad, essentially, which smooths out the dimpled texture of the mattress, which has that traditional bumpy (don't know the right terminology) feel intrinsic to its construction. Recommended!