Tried the new poly mailers... similarly to the stickers... the image/print quality are good. The proofing process is smooth and efficient.  The mailers themselves are on the thinner side but should be fine for a t-shirt or smaller item.  The only issue I had with my order was that whoever packed it and sent it out, did a bad job.  The top 2 corners of all the bags were bent/folded over about an inch to 2 inches and smashed irregularly and now have wrinkled crumpled seam on all of them. 

Nice poly mailer product - Not so nice packing/shipping - a not so new feeling.