Jul 27, 2026Material Notes
What Material Is a Poly Mailer Bag Made Of? A Complete Guide for E-Commerce Sellers
Our poly mailers are made from high quality LDPE material, which is lightweight, waterproof and tear resistant.
Poly mailers are the default shipping bag for apparel, accessories, and small goods. Here's exactly what they're made of and how to choose the right material for cost, durability, and sustainability.
Quick Answer
Poly mailer bags are made primarily from polyethylene plastic, most commonly low-density polyethylene (LDPE), sometimes blended with linear low-density polyethylene (LLDPE) for extra stretch and tear resistance. Lower-cost versions may use high-density polyethylene (HDPE), while eco-conscious brands increasingly choose recycled poly (rLDPE) or compostable bioplastics made from PBAT and PLA blends.
The Main Materials Used in Poly Mailers
- LDPE (Low-Density Polyethylene) — the industry standard. Flexible, water-resistant, and puncture-resistant.
- LLDPE (Linear Low-Density Polyethylene) — often blended with LDPE for extra tensile strength; used in heavy-duty mailers.
- HDPE (High-Density Polyethylene) — stiffer, cheaper, less puncture-resistant; used for lighter, low-cost mailers.
- Recycled Poly (rLDPE) — post-consumer/industrial recycled plastic with performance close to virgin LDPE, often labeled with a PCR% (recycled content).
- Compostable Bioplastics (PBAT/PLA) — break down under industrial composting; look for BPI or ASTM D6400 certification, since "biodegradable" claims vary widely.
Material Comparison
Material | Durability | Cost | Eco-Friendliness | Best For |
|---|---|---|---|---|
LDPE | High | Medium | Low (unless recycled) | General apparel/mixed goods |
LDPE/LLDPE blend | Very High | Medium-High | Low-Medium | Heavier or fragile items |
HDPE | Medium | Low | Low | Lightweight, low-cost shipping |
Recycled Poly | High | Medium | High | Sustainability-focused brands |
Compostable (PBAT/PLA) | Medium | High | Highest (if certified) | Eco-focused DTC brands |
Quick Selection Guide
- Budget shipping → Standard LDPE or HDPE
- Fragile/heavier items → LDPE/LLDPE blend, 2.36–3.5 mil
- Sustainability goals → Recycled poly (check PCR%) or certified compostable
- Regulated markets (EU, California, etc.) → Confirm certifications meet local rules
FAQ
Are poly mailers recyclable? Yes, via store drop-off plastic-film programs — not curbside bins.
LDPE vs. HDPE? LDPE is more flexible and puncture-resistant; HDPE is cheaper but tears more easily.
Biodegradable vs. compostable? Biodegradable lacks a defined standard;
What mil thickness should I choose? 2 mil for light goods, 2.36–3.5 mil for apparel/shoes, 4+ mil for heavier items.
Key Takeaway
Most poly mailers use LDPE or LDPE/LLDPE blends, with HDPE, recycled poly, and compostable bioplastics as alternatives. Choose based on fragility, budget, and sustainability goals — and always request resin type, mil thickness, and certifications from suppliers.