What is a Poly Mailer? Learn More About the Many Benefits and Uses.

Shippo Snippets:

• Poly mailers are one of the most popular and cost-efficient solutions to ship e-commerce goods today
• They’re durable, weather-proof, and come in a wide variety of materials including 100% recycled and bubble-lined
• In some cases, poly mailers might not be the best idea for shipping items that are fragile or don’t fit snugly in the mailer itself
• Poly mailer bags are easier to store than cardboard boxes and can be customized with eye-catching design components to boost your brand and make a statement with your shipping

The Story:

For the uninitiated, poly mailers are a widely used e-commerce shipping option. Technically defined as “polyethylene mailers,” poly mailers are lightweight, weather-proof, easy-to-send envelopes often used as a shipping alternative for corrugated cardboard boxes. Poly mailers are also flexible, self-sealing, and ideal for shipping apparel and other non-fragile items. They offer strong protection against dirt, moisture, dust, and tampering, to ensure your items arrive at your customer’s doorstep intact and secure. 

In this piece, we’ll explore the nitty-gritty behind what poly mailers actually are, various uses, and how they can help e-commerce companies ship merchandise easily, effectively, and on the cheap. 

What Are Poly Mailers Made of?

Poly mailers are made of polyethylene—a light, synthetic resin that composes the most widely-used plastic in the world. Polyethylene is used to produce everything from shopping bags to clear food wrapping, detergent bottles, and even automobile fuel tanks. 

Poly Mailer Varieties

There’s no one-size-fits-all shipping solution with poly mailers. In fact, there are many different types to choose from: 

Layflat Poly Mailers

Layflat poly mailer bags are basically the industry standard. If you’ve ever ordered something from a popular e-commerce company, you’ve probably received it in a layflat poly mailer. It’s a flat plastic bag that can hold a wide array of items, is good for items that don’t need a lot of cushioning, and can be easily affixed with stamps and sealed with a self-adhesive strip. 

Clear View Poly Mailers 

Clear view poly mailers are a solid choice for shipping print materials like catalogs, brochures, and magazines. They’re completely transparent (hence the clear view) on one side with an opaque backside that’s perfect for postage, labels, and other shipping information. 

Bubble-Lined Poly Mailers

For fragile goods that don’t necessarily need a fully packaged box, bubble-lined poly mailers offer extra cushioning and added protection. They’re a low-cost way to send small, delicate items to customers and are usually self-sealable. 

Expansion Poly Mailers

Expansion poly mailers come with an expandable, durable seam along the side that makes it easier and more efficient to ship bulky items. These work well for shipping large items like jackets, sweatshirts, books or binders. 

Returnable Poly Mailers

As we all know, product returns are one of the many inherent costs of doing business online. Returnable poly mailers are a popular way to ship products while planning ahead for potential returns (and are often included in initial shipments). They have two self-seal adhesive closures, offering customers the ability to conveniently return an order directly to your receiving address.

Recycled Poly Mailers 

If you’re trying to build a more eco-friendly, sustainable business, 100% recycled poly mailer bags are made with a mixture of post-industrial and post-consumer materials and have a significantly lower carbon footprint than their virgin counterparts. 

A Cost-Effective Shipping Option

One of the biggest advantages of poly mailers is their affordability, for both purchasing and shipping. For instance, poly mailers can be shipped via USPS First Class Mail, for lightweight packages (under 13 oz), starting at just $0.49. (Try out our USPS postage calculator for an idea of actual discounted rates when using Shippo.) In terms of purchasing, when buying in bulk, poly mailers ring in at around $0.25 per unit, while mailer boxes of a similar size can cost upwards of $1.25 each.

Made for Easy Storage

Spatial relationships don’t have to be your strong suit to see why shipping boxes—even if they’re collapsed—take up more space than poly mailer bags. Cardboard can create a lot of clutter in the packaging process, turning your fulfillment area into a bit of a… hazard zone. Poly mailers, on the other hand, are simple to lay out and pack products into and they don’t require the abundance of assembly that comes with corrugated cardboard boxes. 

Designed for Durability

Weather-proof, water/dust resistant and not easily torn, poly mailers are able to withstand a wide range of conditions without compromising the contents inside. 

Optimal Uses for Poly Mailers

Poly mailers are nothing if not versatile and they work well for fabric-based goods like clothing and textiles. Certain types of hats and shoes ship easily in poly mailers, too. And boxed products that need an added layer of protection like jewelry boxes, shoe boxes, and small toys also travel well in poly mailer bags. 

The important things to consider when shipping with poly mailers is whether the items are fragile (in which case, a bubble-lined poly mailer or corrugated box with padding or void fill might be better) and whether they will fit in a small, medium or large-sized mailer. 

For reference, here’s a little breakdown of sample goods paired with poly mailers of each size: 

Small Poly Mailer (7.5×10.5”)

Could ship soft goods like:

• 2-3 rolled up shirts 
• 1-2 winter hats/ 1 baseball hat 
• 3-4 pairs of socks 
• A folded scarf or towel

Could ship small boxed goods like:

• Accessories like earrings, necklaces, bracelets or pins 
• Small non-fragile ornaments or decorations
• Collectible coins or trinkets 

Medium Poly Mailer (10×13”)

Could ship soft goods like:

• A pair of pants or shorts
• Multiple shirts 
• Multiple winter hats or 2-3 baseball hats (stacked)
• Multiple scarves 

Could ship medium boxed goods like:

• Books 
• Small-to-medium-sized artwork 
• Non-perishable boxed foods like candy 

Large Poly Mailer (14.5×19”)

Could ship soft goods like:

• 1-2 sweatshirts or jackets
• 5-8 shirts 
• 2-3 pairs of pants or shorts 

Could ship large boxed goods like:

• A pair of shoes 
• Well-packed artwork 
• Bulky apparel items like large, fluffy sweaters 

Ways Not to Use Poly Mailers

As versatile as they are, there are certain scenarios where a poly mailer simply won’t cut it for shipping: 

The Contents are Fragile

Products that are breakable or easy-to-damage (fragile or delicate materials, glass, etc.) shouldn’t be shipped in a standard poly mailer but might work in a bubble-lined or padded poly mailer. 

There’s More Than One Item Being Shipped

Unless it’s something like soft apparel, poly mailers aren’t necessarily the best packaging solution when you’re shipping several items at once. A box with air padding is typically a better option, particularly if the items are fragile. 

The Product Doesn’t Properly Fit in the Poly Mailer 

While it might seem easy enough to slip an item into whichever poly mailer you have on hand, poorly filled poly mailers can actually cause confusion during the sorting process for major carriers and USPS alike. Flat spots or gaps can be misread by scanning mechanisms that might lead to shipping errors, damages, delays, or even the dreaded Return to Sender. 

Opting for a stiffer packaging solution like padded mailers, rigid mailers or corrugated cardboard boxes could be your best bet for products that fit poorly in a poly mailer. 

Can Poly Mailers Be Customized?

Customized packaging has been a growing trend in the e-commerce industry for the last few years and it doesn’t appear to be going anywhere anytime soon. And according to the Paper and Packaging Board, a whopping 72% of consumers agree that packaging design can influence their purchasing decision. 

This gives growing merchants a serious opportunity to flex their customization muscles and show customers why buying from them is one of the best decisions out there. 

Poly mailers are easy to customize and can help reinforce brand loyalty and keep customers coming back for more. Here are a few ways to do just that:

• Choose a size (per the examples above) that properly fits your shipment 
• Change its background color to keep with your unique brand attributes 
• Add artwork like a logo or a catchy design 
• Feature compelling or witty text that engages them 

Shippo Can Help

Check out Shippo for a convenient and cost-effective shipping solution.