These are ultra premium 'Slumber Cool' fully zippered mattress encasements with adaptive treated cooling fabric from Pellon in all standard sizes at exceptional pricing. The top is a very high quality softly textured woven jacquard fabric with a 'noise free' waterproof backing. The queen size which I purchased is probably the most popular size, and after applying a 40% off single item coupon (see posts 4 & 8 below) the price was $20.99 plus $8 shipping and applicable state sales tax. This size retails for $112.99 and is currently $107.49 from Overstock or $99 from Amazon for the less expensive more basic mattress protector version. Other available sizes are shown on the linked page at similar discounts.
Coupons for JoAnn are easily found with a simple search to get best possible pricing, although even without a coupon the prices on these are unmatched in my experience. Hope some other SDers can take advantage of this great pricing on a quality product, easily the best mattress protector of many I've tried. These are being shipped directly from the manufacturer so they are factory fresh and not returns.
One word of caution regarding sizing - my mattress is 12" in height which the encasement fits very well, and since the side fabric is stretchable it would also fit mattresses several inches taller. However if you have an extremely thick mattress you'd be well advised to check with Pellon before purchasing to ensure a proper fit.