Postpak Size 4 Bubble Envelope (40 Pack) 41632 Each Postpak Bubble Envelope is made from crisp, tough white paper with a protective and lightweight bubble cushioning inside to keep the contents protected from bumps and scratches. The write-on surface also includes a pre-printed address label with eye-catching red edging and a handy postage guide. Cushioned envelopes for flexible items Bubble cushioning for protection of contents Write-on surface with pre-printed address label Made from tough white paper Size: 4 (320x240mm) Supplied in a pack of 40