Choosing the right poly mailer size is one of the easiest ways to improve your packing workflow. A mailer that is too small can tear, stretch, or slow down your fulfillment team. A mailer that is too large can create a loose fit, waste packaging space, and make orders look less professional.
Poly mailers are best for clothing, soft goods, accessories, and other non-fragile products. They are lightweight, easy to store, and simple to seal. For many ecommerce sellers, they are one of the most practical packaging options for daily shipping.
Start with the folded item size
The best way to choose a poly mailer is to measure the product after it has been folded or packed in the same way you will ship it. This is more accurate than measuring the product flat or on a hanger.
- Small accessories and light apparel usually fit best in smaller mailers.
- Folded T-shirts and leggings often work well in medium sizes.
- Hoodies, sweaters, and multi-item orders usually need larger mailers.
You want enough room for the item to slide into the mailer without forcing it. At the same time, you do not want too much empty space around the product.
Why sizing matters
- Faster packing
- Cleaner presentation
- Lower risk of tearing
- Better use of storage space
- More consistent order handling
If your store ships different apparel categories, it is a good idea to keep a few standard sizes available instead of trying to force every order into one mailer size.
When to size up
You should move up one size when the product uses thicker fabric, the order includes multiple items, the item has extra packaging inside, or you want easier insertion during busy fulfillment periods. Sizing up slightly is usually better than overfilling a narrow mailer.
Pair your mailers with the right supplies
Poly mailers work even better when they are paired with shipping labels and a simple packing workflow. Many sellers use 4x6 shipping labels because they are easy to print and fit common carrier requirements.
If you need help choosing label layouts or print settings, visit our Template Hub. You can also browse all poly mailers to compare sizes and colors.
Poly mailer size guide
Start with the packed item, including any inner bag or wrapping. Measure its width, length, and thickness. A flat mailer needs extra room around the thickness and enough space to close the seal without stretching.
| Mailer size | What to compare | View product |
|---|---|---|
| 6 × 9 | Small, flat soft goods; check the opening and packed thickness. | 6 × 9 white mailers |
| 7.5 × 10.5 | A wider option for compact folded items. | 7.5 × 10.5 white mailers |
| 10 × 13 | Compare with your folded garment and its thickness. | 10 × 13 black mailers |
| 12 × 15.5 | More room for larger folded soft goods. | 12 × 15.5 white mailers |
| 14.5 × 19 | Compare for bulkier garments or multiple soft items. | 14.5 × 19 mailers |
| 19 × 24 | Compare for larger soft-goods bundles. | 19 × 24 black mailers |
Illustrative measurement example (not a tested fit): an item measuring 8 × 10 × 1 inches needs more than an 8 × 10 flat bag. Compare a 10 × 13 mailer as a starting point, then test the packed item: it should slide in easily and the flap should seal flat without pulling on the seams.
These are starting points, not guaranteed fits or usable internal dimensions. Fabric, wrapping, seams, and the sealing flap affect fit. Check the product details and test one packed item before ordering in quantity. Choose protective packaging suited to fragile or sharp items.