250 # 0 – 6 x 10 (usable space: 6 x 23.5 Poly Bubble Mailers Self Sealing Bubble Mailers Our Bubble Mailers are 55 lb. Kraft Paper to laminated flap part until all is stretched in bubble wrap. Most of our competitors are using a 46 lb. paper that is upholstered to the cushioning under the flap 1 in medium only and are not included.