Poly mailer vs box
A poly mailer is usually cheaper and lighter. A box is usually safer for anything that crushes or punctures. Pick the container that matches the item, then compare postage — do not start from the leftover Amazon cube.
Who each option is good for
| Use a poly mailer when | Use a box when |
|---|---|
| Clothes, scarves, soft goods | Shoes, mugs, frames, anything rigid |
| The item can flex without damage | Corners or glass need structure |
| You want to avoid DIM from leftover air | The item will punch through plastic |
Postage impact
Mailers keep actual weight and inches down, which is why they show up in cheap clothing shipments and small packages. Boxes add tare weight and can add DIM. Measure the outer pack: how to measure a package.
A padded mailer is not a box
Bubble mailers help against scuffs. They do not stop a heavy object from folding. If you are on the fence, the box is the conservative pack; then right-size it using the package size guide.
Then price it
Same item, two packs, two quotes. Sometimes the mailer wins by a lot. Sometimes the box is required and you just need the smaller carton. Compare shipping rates after you choose the pack you will actually drop off.
Keep reading
Frequently asked questions
Compare current shipping rates
Oshippy applies the real zone, weight, and size to live USPS and UPS quotes. No stale zone chart.