Mailer

Poly Mailers: Types, Sizes & When to Use Them

Poly mailers are plastic shipping bags — cheaper, lighter, and easier to store than cardboard boxes. Ideal for non-fragile, soft goods like apparel and accessories. They save 30-50% vs equivalent boxes in both material cost and dimensional weight pricing.

Types of Poly Mailers

Standard poly mailers

Basic opaque plastic bags with adhesive closure.

Best for: Clothing, soft goods, most ecommerce apparel

Bubble-lined poly mailers

Poly exterior with bubble wrap lining for shock absorption.

Best for: Lightweight electronics, jewelry, books

Tear-proof poly mailers

Heavier-gauge plastic designed to resist tearing.

Best for: Heavier soft goods, multi-item packs

Compostable mailers

Plant-based plastic that decomposes.

Best for: Sustainable brands and eco-conscious DTC

Printed/branded mailers

Custom-printed mailers with your brand.

Best for: Brands that want a visual unboxing moment

Sizing Reference

Size to about 2 inches larger than your folded/flattened item. 9×12 fits a folded t-shirt; 10×13 fits a hoodie; 14.5×19 fits a jacket.

Practical Tips

•2.5 mil thickness is standard for most ecommerce. 3+ mil for heavy or multi-item shipments
•Sizes commonly: 6×9, 9×12, 10×13, 12×15.5, 14.5×19, 19×24
•Avoid poly mailers for fragile items — they provide zero protection against drops
•Peel-and-seal closure is standard — tape sometimes doesn't stick well to plastic
•Bulk orders from Amazon Business, Uline, or PackagingBrahma offer best per-unit pricing

Frequently asked questions

Are poly mailers cheaper than boxes?

Yes — typically 30-50% cheaper per unit, plus they're lighter (reducing DIM weight costs).

Can I ship fragile items in poly mailers?

Not recommended. Use bubble-lined poly mailers for lightweight fragile items, but boxes are safer for heavy or breakable goods.

What thickness should I use?

2.5 mil is the standard for most ecommerce. 3+ mil for heavier or multi-item shipments. Below 2 mil is flimsy.

Can I ship clothes in a poly mailer?

Yes — ideal use case. Fold the garment neatly, seal in the mailer, add a polybag inside if you want extra moisture protection.

When is a poly mailer the wrong choice?

Anything rigid, fragile, or crushable. Poly mailers are unpadded plastic envelopes — perfect for soft, non-breakable goods (apparel, textiles, plush) but zero protection for anything a stack of packages could crush. Books survive; ceramics don't. If the item has a shape to protect, it needs a box or a padded mailer, not a poly.

What mil thickness do I need?

2-2.5 mil handles most apparel and soft goods; 3-4 mil for heavier or sharper-edged contents that could split a thin bag. Thicker resists tearing and punctures but costs more — match to the weight and edge-sharpness of what's inside. A heavy pair of jeans in a 2-mil bag is a split waiting to happen.

Do poly mailers protect against rain?

The bag itself is water-resistant, but the seams and the self-seal strip aren't waterproof — driving rain on a porch can wick in. For moisture-sensitive soft goods (some textiles, paper goods), bag the item inside the mailer or use a box. Poly resists incidental moisture well; it's not a dry-bag.

Are poly mailers recyclable or sustainable?

Standard poly mailers are store-drop-off film recycling, not curbside — same stream as bubble wrap. Recycled-content and compostable poly-alternative mailers exist and are increasingly popular for apparel brands. If sustainability matters to your buyers, the mailer choice is visible and worth making deliberately.

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