Bubble Mailers

Bubble mailer size chart (#000–#7)

Bubble mailers use a standard numbering system. The number sets the size; usable inner dimensions run slightly smaller than the printed outer size because of the seal seam and bubble lining. Measure your item after any retail box or inner bag is added, then pick the mailer whose inner width and length let it slide in flat with the flap sealing cleanly.

Inner dimensions are approximate and vary a little by manufacturer; exact usable size is listed on each product. When in doubt between two numbers, size up — a mailer that seals flat protects better than one packed to the seam.

Poly vs. kraft bubble mailers

Poly bubble mailers

A lightweight, tear- and water-resistant polyethylene film outer with a bubble lining. The poly skin shrugs off moisture and rough handling, and the mailers are the lightest option — which can lower postage. This is the standard choice for e-commerce fulfillment and anything that might see rain or a wet truck bed.

Kraft bubble mailers

A brown kraft paper outer over the same bubble lining. Kraft gives a natural, recyclable-looking presentation, takes handwriting and stamps well, and offers a slightly more rigid feel. Choose kraft for brand fit, direct-print or label-friendly surfaces, and lower-moisture routes. Poly resists water better; kraft reads more premium and paper-forward.

Self-seal guidance

Nearly all mailers here are self-seal: a peel-off strip exposes a permanent adhesive line on the flap, so you fold and press — no tape or moisture needed. For a clean, tamper-evident seal:

• Load the item so it sits flat and does not push against the flap fold.
• Peel the liner fully, then press the flap down from the center outward to avoid trapping air.
• Leave a little clearance at the top — a mailer stuffed to the flap can pop its seal in transit.
• For heavy or high-value items, run a strip of carton sealing tape over the flap edge as backup.

How to choose the right bubble mailer

• Start with the item's packed dimensions (including any inner box), then find the mailer whose inner size clears it with room to seal flat.
• Pick material by route and brand: poly for water resistance and lowest weight, kraft for a paper look and print/label friendliness.
• Semi-fragile items: bubble mailers cushion against abrasion and light knocks, not crushing. For genuinely fragile goods, step up to a box with void fill.
• High volume: buy by the case pack; larger orders reach free-shipping tiers.

Related collections: Poly Mailers for flat, non-padded shipping bags, Corrugated Boxes for rigid protection, and Void Fill for cushioning inside cartons. For volume pricing or custom sizes, request a bulk quote.

Frequently asked questions

What do the bubble mailer size numbers mean?

The number (#000 through #7) corresponds to a standard size, from smallest (#000, about 4×7" inside) to largest (#7, about 14×19"). Higher number means a larger mailer.

How do I measure for the right size?

Measure your item after adding any retail box or inner bag, then choose the mailer whose usable inner width and length let it slide in and still seal flat. When between sizes, size up.

Are inner dimensions the same as the size printed on the mailer?

No. Usable inner space runs slightly smaller than the outer size because of the sealed seam and the bubble lining. Each product lists its exact usable dimensions.

What is the difference between poly and kraft bubble mailers?

Poly mailers are lightweight and water-resistant plastic film; kraft mailers are brown paper with a more natural, print-friendly look. Poly handles moisture better; kraft reads more premium and takes ink and labels well.

Do bubble mailers self-seal?

Yes. A peel-off strip exposes a permanent adhesive line on the flap, so you fold and press with no tape or water. Press from the center outward for a clean seal.

Are bubble mailers waterproof?

Poly bubble mailers are water-resistant and shrug off rain and damp handling; they are not fully submersion-proof. Kraft mailers offer less moisture resistance.

Can bubble mailers ship fragile items?

They cushion against abrasion and light impacts, which suits semi-fragile goods. For truly fragile items, use a box with void fill instead.

How are bubble mailers sold?

By the case pack. Case counts vary by size and are listed on each product; larger volumes qualify for free-shipping tiers.

Which size is best for books?

A #1 (about 7×11") suits most paperbacks and DVDs; step up to a #3 (about 8×13") for hardcovers.

Can I print or label directly on the mailer?

Kraft surfaces take handwriting, stamps, and shipping labels readily. Poly mailers accept adhesive labels; permanent-marker directly on poly can smear.