Barrier Bubble lining retains air better than alternative cushioning materials. Natural Kraft exterior that doesn't require bleaching or dying to create an "unnatural color" like gold or white. Fully laminated Natural Kraft and air cellular construction provides outstanding stiffness and puncture resistance. Envelope/Mailer Type: Cushioned/Media; Envelope Size: 6 x 10; Closure: Self-Adhesive; Trade Size: #0.