Poly mailers for e-commerce: Co-Ex film, strength and printing options

Poly mailers have become a standard packaging format for online retailers that ship apparel, accessories and other items which do not need a rigid box. They are light, take up little space in the warehouse and protect goods from moisture and dirt. For businesses with high parcel volumes, understanding how these mailers are made helps to choose a product that balances cost, durability and brand presentation.

What a poly mailer is made of

A poly mailer is a flat bag made of polyethylene film with a self-adhesive closure strip. Higher-quality versions use co-extruded film, where several layers are combined in one production step. Each layer has its own function: the outer layer provides tear resistance and a surface suitable for printing, the middle layer makes the bag opaque, and the inner layer supports a reliable seal. This structure keeps the film strong even at low thickness, which saves material.

Film thickness and strength

Film thickness is measured in microns (µm). Lightweight garments and soft goods can be shipped in thinner mailers, while heavier or sharper items need a thicker, more puncture-resistant film. Equally important is the quality of the side seams, since these are the weakest points when parcels are stacked, sorted and loaded. Ask the manufacturer for data on seam strength and tear behaviour, and test samples with your own products before ordering larger quantities.

See also: How Artificial Intelligence Works in Everyday Life

Closure and tamper evidence

The adhesive strip should bond permanently on first contact and withstand low temperatures and longer storage. A good closure leaves visible traces if the bag is opened, which protects against theft and disputes about missing items. Cheaper strips often fail in winter or lose tack in the warehouse, so it pays to check this property early.

Where to find the full range

The complete range of formats and variants is described at https://www.filmar-group.pl/en/products/courier-packaging/poly-maile-co-ex-filbags/, where Filmar Group presents its co-extruded poly mailers as a manufacturer. When you buy directly from the producer, size, thickness and printing can be adapted to your products, and quality stays consistent from one delivery to the next, which is often more valuable for regular buyers than a slightly lower unit price.

Printing and branding

The smooth outer surface takes print well. A logo, brand colours or handling instructions on the mailer turn every parcel into a branded touchpoint, so the customer recognises the sender before opening it. Clarify the minimum run, the number of colours and the printing method with your supplier. Water-based inks are a good choice when sustainability is part of your brand message, and they fit growing customer expectations around eco-friendly packaging.

Typical uses

Poly mailers are used for clothing, textiles, accessories, printed materials, small hardware and returns. They also suit B2B deliveries to branches or the dispatch of samples. For fragile products, a padded bubble mailer or a rigid pack is the safer choice. If you handle both types of goods, many companies keep two or three standard poly mailer sizes in stock next to padded variants to cover the whole assortment.

Recycling and regulation

Mailers made from a single polyethylene material are easier to recycle than multi-material packaging. The EU Packaging and Packaging Waste Regulation (PPWR) raises expectations around recyclability and recycled content, so it is worth asking suppliers about versions with post-consumer recycled film and the certificates that support such claims. Switching early gives you planning certainty and avoids last-minute changes.

Checklist before you order

Check film structure, thickness, seam strength, closure quality, available sizes, printing options, minimum order quantity and sustainability documentation. Compare offers using the same criteria and request samples to confirm performance with your own goods before committing to a larger order.