Poly mailers, also called courier bags or mailing satchels, are the go-to packaging for clothing, soft goods and anything that doesn't need a box. They're light, waterproof, tamper-evident and cheap to ship.
The tricky part is choosing the right size. Too small and the bag splits or won't seal. Too big and you're paying for packaging you don't need, and your product slides around inside.
This guide covers every common poly mailer size, what typically fits in each one, and a simple way to measure your products so you order the right size the first time.
How Poly Mailer Sizes Are Measured
Poly mailer sizes are written as width x length in millimetres, for example 310mm x 405mm. The size refers to the usable bag area, not including the self-seal flap.
Most sizes also have a number such as #02 or #04. These numbers are widely used across the Australian packaging industry, so they're a handy shorthand when you reorder.
One important thing to remember: a poly mailer is flat, but your product isn't. Every centimetre of thickness uses up some of the bag's width and length. A folded hoodie that's 300mm wide and 60mm thick won't fit comfortably in a bag that's 310mm wide.
The Simple Sizing Rule
To find your minimum bag size, measure your product (folded and packed the way you'll ship it) and use this rule of thumb:
- Bag width = product width + product thickness + about 20mm
- Bag length = product length + product thickness + about 30mm (to leave room to seal the flap)
Example: a folded t-shirt that's 230mm x 280mm and 25mm thick needs a bag of at least 275mm x 335mm. A #03S (280mm x 380mm) is a comfortable fit.
Poly Mailer Size Chart
Here are the sizes in our poly mailer range, with typical uses for each:
| Size | Dimensions (W x L) | Typically fits |
|---|---|---|
| #00 | 160mm x 230mm | Jewellery, phone cases, socks, small accessories |
| #01 | 190mm x 260mm | Kids' clothing, singlets, scarves, a single thin t-shirt |
| #02W | 200mm x 350mm | Long, narrow items such as rolled leggings or belts |
| #02S | 225mm x 355mm | Folded t-shirts, swimwear, A4 documents |
| #02 | 255mm x 330mm | One or two t-shirts, leggings, activewear, A4 flat items |
| #03S | 280mm x 380mm | Shirts, light knitwear, two or three folded tees |
| #03 | 310mm x 405mm | Hoodies, jeans, dresses, our most popular size for fashion |
| #03W | 280mm x 420mm | Longer garments, folded pants, tall items |
| #04S | 340mm x 440mm | Jumpers, multiple garments, small towels |
| #04 | 350mm x 480mm | Jackets, multi-item orders, bed sheets |
| #05 | 400mm x 500mm | Bulky knitwear, beach towels, cushion covers |
| #05S | 420mm x 450mm | Wide, squarer items such as folded throws |
| #05V | 400mm x 550mm | Coats and longer bulky garments |
| #05W | 430mm x 545mm | Puffer jackets, bath sheets, bundled orders |
| #06S | 490mm x 550mm | Quilt covers, large multi-item orders |
| #06W | 450mm x 650mm | Long bulky items, rolled bedding |
| #06 | 500mm x 650mm | Pillows, doona covers, soft toys |
| #07 | 600mm x 650mm | Vacuum-packed doonas, large soft toys |
| #08 | 650mm x 750mm | Bedding sets, wholesale garment bundles |
| #09 | 750mm x 900mm | Bean bag covers, large cushions, bulk soft goods |
| #10 | 950mm x 950mm | Oversized soft items and large bundles |
"Typically fits" is a guide only. Garments vary a lot in bulk, so always test with your own products before ordering in volume.
Which Sizes Do Most Sellers Use?
If you sell clothing, you'll probably cover 90% of orders with just two or three sizes:
- #02 (255 x 330mm) for single small items
- #03 (310 x 405mm) for single larger items and two-item orders
- #04 (350 x 480mm) or #05W (430 x 545mm) for bulky items and multi-item orders
Sticking to a few core sizes makes packing faster and lets you buy each size in larger, cheaper quantities. Our guide to buying shipping supplies in bulk explains the savings.
Colours and Materials
Poly mailers aren't just white anymore. Choosing a colour is an easy, low-cost way to make your parcels stand out:
- White poly mailers: clean, classic and easy to write on
- Black poly mailers: sleek, premium and fully opaque
- Hot pink poly mailers and rose pink mailers: great for fashion, beauty and gift brands
- Compostable mailers: a plastic-alternative option for eco-conscious brands (read our guide to what compostable actually means)
When a Poly Mailer Isn't the Right Choice
Poly mailers give almost no crush protection. For anything fragile, rigid or valuable, use a padded or rigid option instead:
- Small fragile items like cosmetics or electronics: bubble mailers
- Flat items that mustn't bend like prints and photos: rigid mailers
- Anything breakable or heavy: shipping boxes and cartons
Not sure which way to go? Our comparison of satchels vs boxes vs mailers covers the pros and cons, and our guide to choosing mailers for apparel goes deeper on clothing.
Quick Tips for Packing Poly Mailers
- Fold garments neatly and consider a clear poly bag as an inner layer to keep items clean and presentable.
- Press the air out before sealing so the bag sits flat and is less likely to snag on sorting equipment.
- Stick your shipping label on a flat area away from the seal and folds.
- Don't overstuff. A bulging mailer is more likely to split in transit.
Order Poly Mailers From eBPak
We stock poly mailers in more than 20 sizes and several colours, in pack sizes from 100 through to wholesale cartons. Browse the full poly mailer range or order a few sizes to test with your own products before you buy in bulk.