If you're shipping soft goods on Etsy, Amazon, or eBay, poly mailers are your cheapest and fastest shipping option. But walk into an office supply store and you'll pay $0.50+ per mailer. Buy the wrong size online and you're stuck with 500 unusable bags.
After shipping thousands of orders, here's what actually works.
Quick Picks
| Product | Best For | Size Range | Price | Link |
|---|---|---|---|---|
| RUSPEPA Poly Mailers 💰 BEST VALUE | Most sellers, budget pick | 6x9 to 19x24 | ~$0.07/ea | Amazon |
| Metronic Poly Mailers 🏆 BEST OVERALL | Premium quality, thicker | 6x9 to 24x24 | ~$0.12/ea | Amazon |
| UCGOU Poly Mailers ⚡ BEST FOR CLOTHING | Apparel sellers, clean seal | 10x13, 12x15 | ~$0.09/ea | Amazon |
| Shop4Mailers 📦 BULK PRICING | High-volume shops (1000+) | All standard sizes | ~$0.05/ea | Amazon |
Why Poly Mailers Beat Boxes
Poly mailers cost 5-10x less than boxes and weigh almost nothing. That matters when you're paying dimensional weight on every shipment.
A 10x13 poly mailer weighs about 0.3 oz. The same size box weighs 4-6 oz before you add packing material. On a 1-pound package, that extra weight bumps you from 4 oz First Class to 8 oz, adding $1.50-$2 to every shipment.
Use poly mailers for anything flexible that doesn't break: clothing, textiles, soft accessories, non-fragile home goods, paper products.
Switch to boxes when you're shipping glass, ceramics, electronics, or anything that needs structure.
Size Guide: Which Mailer for What Product
Getting the size right matters. Too small and you're cramming products in like a suitcase. Too large and you're paying for dimensional weight you don't need.
6x9 - Jewelry, small accessories, phone cases, socks, face masks. Anything that fits in your palm.
9x12 - T-shirts, tank tops, scarves, thin books, small plush items, cosmetic bags.
10x13 - The workhorse size. Folded jeans, hoodies, small blankets, bundled candles, multiple items in one order. Most clothing sellers stock this size.
12x15.5 - Bulkier clothing, winter coats, thick sweaters, small pillows, bath towels.
14x17 - Comforters, large blankets, multiple clothing items, fabric by the yard, oversized hoodies.
19x24 - Bedding, curtains, large textile orders, bulk clothing shipments.
Measure your most common products before ordering. Add 1-2 inches to each dimension for easy packing. If you're between sizes, go smaller to save on shipping weight.
Material Types: Mil Thickness Explained
Poly mailers come in 2.5 mil and 3.5 mil thickness. The difference feels minor in your hand but shows up when customers receive damaged packages.
2.5 mil is the standard. It's what most Amazon sellers use. Strong enough for normal handling, cheap enough to buy in bulk. Works fine for most products unless you're shipping cross-country or internationally.
3.5 mil is thicker, more puncture-resistant, and costs about 30% more. Use it for:
- International shipments (more handling = more abuse)
- Heavier items (3+ pounds)
- Products with sharp edges or hardware
- Premium brands where presentation matters
Don't waste money on 3.5 mil for lightweight clothing going domestic First Class. Save the upgrade for where it counts.
Most poly mailers are made from LDPE or coextruded film. Both are waterproof, tear-resistant, and recyclable at most grocery store drop-off bins. The coextruded versions have better puncture resistance because they layer different plastics.
Self-seal adhesive strips are standard now. Skip anything with peel-and-stick that requires removing a backing strip. You'll waste hours over thousands of shipments.
Top Poly Mailers: Detailed Reviews
RUSPEPA Poly Mailers 💰 BEST VALUE
These are my go-to for most shipments. At $0.07 per mailer in bulk (100-pack), they hit the sweet spot between quality and cost.
The 2.5 mil thickness handles normal USPS and UPS shipping without issues. I've sent thousands of these and damage complaints are rare. The adhesive seal is strong and stays closed.
They come in every size you need, from 6x9 up to 19x24. Stock up on your two most common sizes and you're covered.
Downsides: They're not premium. The material feels thinner than Metronic if that matters for your brand. And the white color shows dirt if you're storing them long-term in a dusty warehouse.
Best for: Budget-conscious sellers shipping 50-500 orders per month who need reliable basics.
Metronic Poly Mailers 🏆 BEST OVERALL
If I'm shipping premium products or international orders, I use Metronic. The 3.5 mil thickness is noticeably sturdier.
These feel professional in hand. The seal is aggressive and I've never had one come open during shipping. The material has better tear resistance, which matters when USPS throws your package into a truck with 200 other boxes.
At $0.12 per mailer, they cost about 70% more than RUSPEPA. Worth it for high-value items or when customer presentation matters. Not worth it if you're shipping basic tees at thin margins.
They offer more color options too - grey, pink, teal - if you want branded packaging without custom printing.
Best for: Sellers with premium products, international shippers, or anyone who's had damage issues with thinner mailers.
UCGOU Poly Mailers ⚡ BEST FOR CLOTHING
UCGOU specializes in the 10x13 and 12x15 sizes that clothing sellers use most. Their 2.5 mil mailers run about $0.09 each in 200-packs.
What sets them apart is the clean seal. Other brands sometimes have adhesive that gunks up or leaves residue. UCGOU's seal is clean, which matters when customers are opening your package.
The material is slick, so folded shirts slide in easily. Sounds minor until you're packing your 100th order of the day.
They also offer designer patterns if you want your packaging to stand out without paying for custom printing. The marble and leopard prints look sharp.
Best for: Clothing sellers, boutique shops, anyone packing primarily 10x13 or 12x15 orders.
Shop4Mailers 📦 BULK PRICING
Once you're shipping 200+ orders per month, Shop4Mailers offers the best per-unit pricing. Their 1000-packs drop the cost to around $0.05 per mailer.
Quality is solid - these are 2.5 mil with a reliable seal. Not fancy, but they do the job. Available in all standard sizes.
The catch is storage. A case of 1000 mailers takes up space. Make sure you have room before ordering.
They also offer colored options in bulk, which helps with inventory organization if you're shipping multiple product lines. Blue for one SKU category, pink for another.
Best for: High-volume sellers, fulfillment centers, anyone doing 1000+ shipments per month.
Poly Mailers vs Boxes: When to Switch
Use poly mailers when:
- Product is soft and flexible
- Item value is under $50 (less risk)
- Shipping domestic First Class or Ground
- Weight is under 2 pounds
- You need to pack fast (poly mailers are 3x faster)
Use boxes when:
- Shipping fragile items (glass, ceramics, electronics)
- Item value is over $50
- Customer expects premium unboxing experience
- Product has rigid shape that needs protection
- Shipping internationally with lots of handling
Some sellers hybrid it. Ship most orders in poly mailers but upgrade orders over $75 to boxes with branded tissue and thank-you cards. Customers notice.
If you're using both, check out our label printer guide for equipment that handles high shipping volume.
Buying in Bulk: Real Cost Savings
Poly mailer pricing drops dramatically when you buy larger quantities. Here's the actual math on 10x13 mailers:
25-pack: $0.40 per mailer ($10 total) 100-pack: $0.15 per mailer ($15 total) 200-pack: $0.09 per mailer ($18 total) 500-pack: $0.07 per mailer ($35 total) 1000-pack: $0.05 per mailer ($50 total)
If you're shipping 100 orders per month, buying the 500-pack instead of 100-packs saves you $96 per year on this one item. Not life-changing, but those savings add up across all your supplies.
The break-even point is about 50 shipments per month. Below that, stick with smaller packs so you're not tying up cash. Above that, bulk buying pays off fast.
Storage tip: Keep your most-used size within arm's reach and less common sizes on a shelf. Stack them flat to save space.
Common Questions
Can poly mailers go through the mail wet?
Yes. Poly mailers are waterproof and USPS trucks aren't climate-controlled. Rain won't hurt them. Just make sure your label is either thermal (waterproof) or covered with clear packing tape.
Do I need custom branded poly mailers?
Not unless you're a larger brand. Custom printing requires 1000-5000 minimum orders and costs 3-5x more per mailer. For most Etsy and Amazon sellers, plain mailers plus a printed thank-you card or sticker work fine.
Can customers recycle poly mailers?
Most poly mailers are LDPE #4 plastic. Many grocery stores have plastic bag recycling bins that accept them. They're not curbside recyclable in most cities. Some brands now offer biodegradable or compostable options, but they cost 2-3x more.
What if the mailer is too big for my product?
Fold the excess over and seal it with clear packing tape. Or fold the product to reduce size. Slightly oversized is fine. 3+ inches too big looks sloppy and increases dimensional weight.
Should I use bubble mailers instead?
Bubble mailers cost 2-3x more than poly mailers. Use them for semi-fragile items like jewelry, cosmetics, or small electronics. For clothing and soft goods, poly mailers are plenty.
How do I calculate shipping costs with poly mailers?
Most poly mailers are under 1 oz, so they don't affect your shipping weight meaningfully. A 10x13 mailer adds about 0.3 oz. Factor that into your total package weight when calculating rates on Pirate Ship or your shipping platform.
Can I reuse poly mailers?
Technically yes, but the adhesive seal is one-time use. You'd need tape to reseal it, which looks unprofessional. At $0.05-$0.10 per mailer, just use a fresh one.
Next Steps
Poly mailers are the easiest shipping upgrade you can make. They cut costs, speed up packing, and keep products safe.
Start with a 100-pack of 10x13 mailers if you're unsure. That size covers most common products. Add other sizes as you see what you actually need.
Once you've got packaging dialed in, the next bottleneck is printing labels. Check out the best label printers for high-volume sellers.
For more shipping and packaging recommendations, browse the full gear guide.