The foam used in a BedRug is closed cell. The fuzzy part is probably polypropylene, neither absorb water. I used it for several months in the Winter, where it was exposed to heavy rains and routine truck washing, before installing my shell. No problems at all.
Dogarms wrote: I’m going to go against the grain and suggest that unless you intend to use the bed for hard work a BedRug liner might be just what you’re looking for. It is a soft, foam backed, water proof, and stain resistant liner that is very durable for all but really heavy work and it is very easy on the body, should you find yourself crawling around back there. It’s also easy on the things you carry. Most of the stuff I carry around is in the nature of furniture or sound equipment. It is great for that. But I’ve hauled more substantial items as well. I have a shell on my truck, but you don’t have to cover it. After five years the liner still looks and feels new.
Count me as one of those in favor of the spray-in liners. I've had drop-in's, bed-mats and spray-ins. I use the truck as a truck, but also want it to look good. The spray-ins (have had Line-X and Rhino-Liner) besides protecting the bed give a sure grip surface for carrying items. They also serve as a sound-deadening material. On my current Ram I've got a Line-X and a roll-up tonneau from X-tang.