BUBBLE MAILER DIMENSION. 4x8 inch padded envelopes(usable size-4x7"), with opaque purple poly film. The bubble envelopes feel nice to the touch and are perfect for handwriting, labeling and stamping. COST-EFFECTIVE BUBBLE MAILERS. The padded envelopes are lightweight and water-resistant. Lower the shipping cost of your business and protect your products on the rainy or snowy day. SELF SEALED ENVELOPES. The adhesive on the fold-over flap is strong enough and goes end-to-end. There's no need reinforcement tape and it doesn't come apart unless you tear it up.