Custom Bubble Mailers: An RFQ Checklist for Size, Cushioning, Closure and Print

“What size?” has at least three answers: outer dimensions, opening width and usable internal dimensions after sealing. Give the supplier the product's maximum length, width and thickness, protrusions, weight, units per mailer and desired loading clearance. For thick, irregular or sharp-edged items, send a real sample or 1:1 mock-up. Outer size alone can produce a bag that accepts the item but cannot close flat.

Item	Buyer input	Sample check
Load	Maximum dimensions, weight, fragile points, units	Pack the real product; inspect mouth and seal stress
Usable size	Internal length and width, allowance for thickness	Measure before and after closure
Cushioning	Bubble orientation, layer structure, extra insert	Inspect contact points after packing and transit
Appearance	Material colour, print area and artwork	Check layout, colour and barcode on a physical sample

If the product needs mainly dust or moisture protection and little cushioning, compare a poly mailer. If it needs a bubble structure, start with the poly bubble mailer product page and approve a sample.

Common options include a polyethylene outer layer with a bubble inner layer, a paper-based outer layer with bubble cushioning, or a plain mailer combined with a separate insert. Neither “paper is premium” nor “thicker is safer” is a sufficient specification. Identify crush and scratch sensitivity, moisture exposure, labelling, repeated sorting, wet handling and any return-in-original-bag requirement.

A polyethylene outer layer can support discussion of moisture resistance, heat sealing and print, but finished performance depends on the full construction and closure. A paper-based outer layer offers a different look and writing surface; wet handling, abrasion and recycling classification need to be assessed for the actual laminate and local system. For a recyclability or environmental claim, verify the market rule and finished-product evidence rather than relying on the name of the outer layer.

For electronics, glass or sharp-edged goods, a bubble layer may not address every hazard. Test the real product, any insert and final mailer together.

A self-seal strip, tear strip and second adhesive strip serve different jobs: first closure, controlled opening and return sealing. They are not interchangeable. State strip width, bonding surface, adhesive and release liner, application temperature, time after closing and whether the bag must reseal. The courier-bag closure guide expands on these choices.

ASTM D3330/D3330M-04(2025) provides methods for measuring peel adhesion of pressure-sensitive tape. It can help define strip test conditions and lot consistency, but one peel value does not prove that a finished mailer will stay closed throughout shipment. Test the real bonding surface, environment and complete package.

Approve print separately: artwork revision, printable area, placement tolerance, barcode readability and whether folds or seals obscure information. Retain a signed physical sample before volume production.

ISTA 3A is a general-simulation procedure for individual parcel shipments up to 70 kg. Whether it fits your project depends on the product, mailer shape, route and carrier. It evaluates the product and package combination; it is not a universal certificate for a bubble film material. Agree another procedure with the test provider when 3A is not representative.

Record product condition before and after testing, tears in the mailer, closure opening and damage to print or labels. For flat, irregular or sharp-edged items, inspect local bubble collapse, corner puncture and mouth loading. If the real pack uses a carton, insert or tape, include it in the test sample. A passing prototype does not remove the need to review later material or construction changes.

Send these details together so suppliers quote the same construction:

1. Product photos, maximum length/width/thickness, unit weight and units per mailer; flag sharp corners, glass, electronics or scratch-sensitive finishes.
2. Usable internal size, opening direction, loading method and tolerance. If unknown, provide the product for sampling.
3. Outer material, bubble structure, colour, print sides and artwork quantity. For any environmental or compliance claim, state the sales market and documents needed.
4. Closure type, tear or return-seal requirement, label and barcode position.
5. Target shipping route, storage, outer carton or insert, and preferred sample-validation method.
6. Forecast quantity, delivery lots and artwork revision. Confirm minimum order, sampling, lead time and price against the specific construction and current capacity.

The poly bubble mailer product page is a starting point. For a broader comparison with plain mailers and bubble wrap, see the e-commerce packaging guide. Do not treat one material parameter as a guarantee for the full route.