Apologies for not reading all of the pages.....lots of them! Could someone explain what PUL fabric is - I assume it is waterproof, what is the best to use and where from?

Oh and for those who use velcro for fastening - do you find it picks up fluff and eventually doesn't work? I have seen one pattern that makes a double thing on the hook corners to turn over the hook before washing to prevent this but am still not sure it would work.