Well put arguments, all. I think the "fleece" term (I saw it in print) is in reference to "blown glass", or fiberglass fibers. But when blown as spun, they adhere to each other and form a porous yet rigid structure.
I'm going to look at these under a 'scope at the lab tomorrow and see what I see.

Mike, thanks bud. I ain't goin' nowhere but off the deep end.
The boy (mine) got a job at Mahle Inc. in Atlantic, Iowa. Leaves on Saturday for a 6 month internship. Replacing the radiator in his '97 Town Car tomorrow PM to show him I'll work to save the $200 charge the garage wanted. At least they found the slow leak for me.
I ain't made of money, boy...