Ship in a poly mailer when the product is soft, light, flexible and not breakable, such as T-shirts and hoodies. Ship in a box when it is rigid, fragile, premium or needs a branded unboxing. Most small online sellers end up using both, matched to the product. TBPB makes custom boxes with no minimum order.
Reviewed by the TBPB packaging team, October 2026.
Quick facts
| Item | Answer |
|---|---|
| Minimum order (TBPB boxes) | None. Order one box or thousands |
| Poly mailer fits | Soft goods that can bend without damage |
| Box fits | Rigid, fragile, premium and gift items |
| Main trade-off | Lower weight and unit cost versus protection and presentation |
| How to decide | Product fragility, shipped weight, brand experience, return rate |
When is a poly mailer the right call?
A poly mailer is right when the product can be folded, squished and survive. Apparel, soft accessories and bagged items are the standard cases. The mailer is light, so the parcel weighs little, and it takes almost no storage space until you use it.
The limits are just as clear. It offers no crush protection, and a sharp corner can puncture it. It also cannot present a product the way a printed box can. If your customers are expecting a gift, a poly bag works against you.
When is a custom box the right call?
A box is right when the product has a shape that needs to survive, or when the unboxing is part of what the customer is buying. Candles, cosmetics, electronics accessories, food gifts and anything with glass or a rigid structure belong in a box.
A box also lets you print inside and out, add an insert if the spec allows, and ship something that looks the same on delivery as it did when you packed it. For shipping boxes see our mailer boxes guide and corrugated boxes guide, and our mailer box range.
How do I compare the real cost of each?
Add up what the order costs you start to finish, not the unit price. Include the packaging, the shipped weight, the damage rate you see, and the cost of replacing a broken item.
| Cost line | Poly mailer | Custom box |
|---|---|---|
| Packaging unit | Lower | Higher |
| Shipped weight | Lower | Higher |
| Damage and replacement | Higher for fragile goods | Lower if the fit is right |
| Brand impression | Minimal | Strong |
Worked example: you sell a ceramic mug that ships by itself. If a poly mailer gets even a few of every hundred broken in transit, you lose the mug, the postage on both shipments, and probably the customer. A properly fitted box lowers that rate. The point is that the mailer saves cents on every order and costs you in the orders that fail. For a full cost explanation read how much custom boxes cost.
Do I have to choose just one?
No, and splitting is usually smarter. Put shirts in mailers and mugs in boxes. If one product is both soft and premium, such as a cashmere scarf, a box with a printed lid can justify its weight in perceived value.
A bag option sits between the two. If you are looking at printed bags instead, see our custom bags. Pick whichever protects the specific product; the title of the category matters less than the loss rate.
How do I keep a box from adding shipping cost?
Right-size it. Carriers charge on weight and on package size, and an oversized box costs more than a snug one. Measure the product, add only the clearance it needs, and avoid filling empty space with extra paper when a smaller box would do.
- Measure the product in inches at its longest, widest and deepest points.
- Add clearance for any wrap or insert, and nothing more.
- Weigh the packed order on a kitchen or postal scale.
- Ask your carrier how they price packages of that size and weight before you commit to a run.
We do not quote carrier rules here, because they change. Check your carrier’s current published guidance.
What is the honest case against a custom box?
It weighs more, costs more per order and takes more storage space. If you ship a soft, low-margin item in volume, a box may eat your margin without adding anything the customer notices. In that case a poly mailer is the correct choice, and we would rather say so than sell you something you do not need.
Fit also matters. A box too large for the product lets it slide and costs more to ship. Size it to the product with clearance, and use our kraft versus white guide to choose the board look.
Questions buyers ask
How to order
Send the product dimensions, packed weight and quantity through the quote form, even if you only need one box to test. We return a dieline and a price. If you hold a written quote for the same specs elsewhere, our price-beat guarantee applies. Free design help, free samples and free shipping are included.
Are poly mailers cheaper than boxes?
Usually the mailer itself costs less and weighs less, which can lower shipping. But a damaged order costs a refund and a reshipment, so compare the cost of the packaging plus your expected loss, not the unit price alone.
Can I ship fragile items in a poly mailer?
Not safely. A poly mailer stops water and scuffs but not crushing or impact. Fragile, rigid or sharp-cornered items belong in a box with a fit that stops movement.
Do custom boxes make customers more likely to buy again?
We do not have a verified statistic for that, so we will not quote one. What we can say is that a printed box is the first thing a customer touches, and it carries your brand into the home in a way a plain bag does not.
Can I use both a box and a poly mailer?
Yes. Many sellers put soft goods in poly mailers and breakable or premium items in boxes, or put a poly bag inside a box for moisture protection. Split by product, not by habit.
Is there a minimum order for custom boxes?
No. Order one box or ten thousand. That means you can test a custom box on your top product without committing to a pallet.
How do I get a quote and a dieline?
Send the product dimensions, packed weight and quantity through the quote form. We return a dieline and a price, even for one box.
