A poly bubble mailer is a plastic shipping envelope lined with bubble wrap. It suits small, flat, not-very-fragile items: jewellery, accessories, cosmetics, small parts. For clothing a plain poly mailer is often enough; for anything fragile, heavy or hard-cornered, use a box. Measure the mailer once it is filled, then compare prices using those real dimensions.
What is a poly bubble mailer?
It is a soft pouch with a plastic (polyethylene) or kraft paper outside and a layer of bubble wrap inside, closed with a self-seal adhesive strip. The plastic resists water and tearing, and the bubbles absorb small knocks, without the bulk or weight of a box.
For an online shop that mostly sends small items, it is often the most practical packaging: it stores flat, packs fast and adds very little to the parcel weight.
Bubble mailer, poly mailer or box
| Packaging | Protection | Best for | Avoid for |
|---|---|---|---|
| Poly mailer (no bubbles) | Water and dirt, no cushioning | Clothing, textiles, soft goods | Anything that can break or bend |
| Poly bubble mailer | Water + small knocks | Jewellery, accessories, cosmetics, small parts, thin books | Glass, fragile electronics, heavy items |
| Kraft bubble mailer | Small knocks, less water-resistant | Same uses, paper outside | Parcels exposed to rain or snow |
| Corrugated box | Crushing + knocks | Fragile, heavy, hard-cornered or high-value items | Small soft items (you pay to ship air) |
A simple rule: if the item would survive a fall off a table inside a mailer, the mailer is enough. If it could break, bend or push through the wall, move up to a box with cushioning.
Choosing the right size
- Sizes are listed as inside dimensions. Leave some extra length and width for the item’s thickness, or the adhesive strip will not close flat.
- A mailer that is too big lets the item slide and bend. One that is too small strains the seal, which can open in transit.
- Keep two or three sizes that cover most of your products rather than a different size for every order.
- Press the adhesive strip flat along its full length. Packing tape over it adds security for a heavier item.
Every carrier sets its own rules for soft packaging: maximum size and weight, how non-rectangular parcels are handled, and sometimes a fee for packaging it treats as non-standard. These rules vary by carrier and service: check the carrier’s packaging guide and confirm the limits at the quote step.
Measuring a mailer for pricing
The price depends on the weight and dimensions of the parcel ready to go, not the empty mailer. Once the mailer is filled and sealed:
- Measure the length and width lying flat.
- Measure the thickness at its thickest point: that is the parcel’s third dimension.
- Weigh the complete parcel, mailer included, and round up rather than down.
A thin, light parcel often stays under its dimensional weight, which is why mailers are popular for small items. To check, our free dimensional weight calculator (/tools/dimensional-weight) takes centimetres or inches.
Recycling and your brand
A poly bubble mailer combines plastic and bubbles, and a kraft one combines paper and plastic. These mixed materials are not accepted in every recycling bin: rules vary from one municipality to the next. If your customers care, tell them how to dispose of it, or offer an all-paper option for items that allow it.
Mailers also work for returns: a second adhesive strip lets the customer send the item back in the same pouch.
Compare the price with your real dimensions
MesColis is not a carrier. When you create a shipment, choose “Own packaging”, enter the weight and dimensions of the filled mailer, and we show the carriers and services that serve your lane side by side, each with its total price. Your usual sizes can be saved and picked in one click on the package step.
Do not confuse your own bubble mailer with the carrier “Envelope” option, which is for documents only, or with the Courier Pak the carrier supplies: those are separate choices on the package step.
With a free MesColis account, no contract and no minimum volume, you compare the carriers that serve your lane before you buy the label.