Size range
Large Poly Mailers
Searches for large poly mailers almost never come from someone who has already chosen a size. They come from someone whose current mailer keeps splitting, or who has just added a heavier product and needs to know what to order next.
So this page is a decision rather than a description. It sets out what changes as mailers get bigger, which of the three large formats suits which kind of load, and the two mistakes that cost the most when you size up.
From$0.30per unit, indicative — your quotation is priced against your own specification
Price large poly mailers
A short brief is enough to start. We come back with a written specification and a price.
What changes as a mailer gets bigger
Three things shift, and only one of them is obvious.
The obvious one is capacity. The two that catch people out are load behaviour and cost structure.
Load behaviour: a small mailer is held rigid by its contents. A large one is not. Slack air, an uneven load or a hard corner all turn into movement, and movement is what opens seals and tears corners. Sizing up means changing how you pack, not just what you buy.
Cost structure: a bigger bag costs more per unit, holds fewer per carton, and produces a parcel that may fall into a different shipping band. Sometimes consolidating four parcels into one large mailer saves money; sometimes it crosses a threshold and costs more. It is worth weighing a packed sample before you switch a whole flow.
Which large format for which load
Start from your heaviest routine order rather than your average one — that is the order that decides the size.
| If you ship… | Start with | Why |
|---|---|---|
| One heavyweight hoodie or jacket | 14.5x19 | Fills the bag, so there is no slack air to let the load swing. |
| Three to five folded garments | 19x24 | Enough footprint to lay the load flat rather than stacking it into a lump. |
| A bedding or towel set | 19x24 | Compresses evenly and carries no hard corners. |
| Cushions, quilts or square soft goods | 24x24 | A square load fills a square footprint without wasting corners. |
| A boxed item inside a mailer | Reconsider | Hard corners in a flexible bag concentrate load; a carton or cushioned mailer is safer. |
Two expensive mistakes when sizing up
Buying one size larger than you need
Slack air makes a parcel less stable, not more forgiving. An over-large mailer damages more often than a correctly sized one, and costs more per unit as well.
Keeping the light film when the contents got heavy
Sizing up usually means the contents got heavier too. Carrying the same film weight into a bigger format is where most seal failures come from.
Both are avoided the same way: pack a real order into a sample, weigh it, and drop it once from bench height before you commit to a run.
When large is not the answer at all
Sometimes the problem is not room. If the contents are arriving damaged rather than arriving in a burst bag, more space will not fix it — cushioning will. A bubble-lined format protects contents from impact in a way plain film cannot, at the cost of a larger outer dimension for the same interior. The differences between the protective constructions are set out in the protective mailer comparison, which is the better place to start if damage rather than fit is your problem.
How to move to a larger size without over-ordering
Request samples of two candidate sizes
Not one. The comparison is what tells you which is right.
Pack your heaviest routine order into each
Use your real fold and your real inserts, packed by the people who pack for you.
Weigh and measure both packed parcels
Check them against the shipping bands you actually buy on.
Order the smaller one that closes without strain
If both work, the smaller size is cheaper per unit and travels better.
Split the first order if you are unsure
Running two sizes on one order shares the setup and lets you settle the question with real volume.
Questions about large poly mailers
What counts as a large poly mailer?
In practice, anything from around 14 inches across upward. Below that the contents keep the parcel rigid; above it the packing method starts to matter as much as the bag.
Which large size should I order first?
The smallest one that takes your heaviest routine order without the seal straining. Sizing up beyond that adds cost per unit and leaves slack air, which makes parcels less stable rather than more.
Do large mailers need a heavier film?
Usually, because the contents that need a large bag are heavier. Carrying a light film into a large format is the most common cause of seal failures we see.
Can I order several large sizes on one run?
Yes, and it is often the economical way to settle the question. Where the artwork and specification match, setup is shared across the sizes on the same order.
Not sure which large size to order?
Tell us what you ship and how heavy a typical order is. We will recommend a size, say why, and quote it.