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Need Strong Mailing Bags? Choose Heavy Duty Polythene

Polythene postage bags have transformed the way we buy clothes. And there’s no way to overstate that. Shipping orders with a returns bag, with a negligible cost to the seller, has made it possible for customers to buy, try – and return items that don’t fit.

Sure, this comes at a carbon cost; moving all that clothing back and forth isn’t carbon-neutral yet. But as long as consumers prefer convenience over all else, polythene mailing bags make the impact much lower than any other material currently available.

Using polythene bags for clothes is just the tip of the iceberg. Mailing bags can be used for tons of products, from big sacks of pet food to bulk orders of small boxed items. However, not all polythene bags intended for soft items are up to the task of sending solid or pointy packages – which can notch the bag and render it ineffective.

For cases where heavy or angular items need to be sent in a mailer bag, you need strong mailing bags. And while polythene is still the best material for the job, it’s got to be thicker for heavy duty applications.


Extreme closeup of a red postbox in daylight


Heavy duty polythene mailing bags

Mailer bags for clothing and general items are typically 200 gauge to 250 gauge in thickness (approximately 50-60 microns), which is classed as medium duty polythene. This range is perfect for things like clothing and cuddly toys, with ample strength to protect soft, moisture-sensitive products. They’re still hard to tear open, even at this middling gauge.

For anything bulkier or pointier, a heavier gauge of polythene should be used. Heavy duty polythene ranges from 500 gauge to 800 gauge in thickness (125 to 200 microns), and may be required for things like bolts and trade hardware, heavy boxed goods, bulk orders of gusset bagged foods and the like.

Read more: Heavy Duty Polythene Thickness

But do heavy duty mailer bags add to postage costs? Unsurprisingly, tripling the thickness of polythene to make strong mailing bags will make each bag three times heavier. But we’re talking about a material that weighs less than a gram per cubic centimetre. Tripling its weight will of course have an impact on shipping costs over vast quantities – but compare this to the alternatives like paper, cardboard and wooden crates, and it becomes very clear that polythene is practically massless next to these heavyweight materials.

The so-called alternatives offer less protection, cost more, reduce shipping volumes and have a far larger carbon footprint as a result. This is what’s important to price-conscious consumers and the companies that cater to them – and around this time of year, it’s even more important than usual.

Black Friday and Christmas are coming…

The big online shopping season is upon us, and mail orders will be on the up – big time. This often means that businesses need to hire seasonal staff on packaging lines and in logistics chains, helping with the sudden influx of orders. Preparing for the rush with strong mailing bags is a foolproof way to speed up the process without shelling out additional cash, or sacrificing your product. Heavy duty polythene mailer bags let you keep costs low during seasonal peaks, while keeping productivity high.

What are heavy duty mailer bags used for?

Anything and everything! But here are a few examples of great uses for heavy duty polythene mailing bags.

Ecommerce packaging

Online retailers can use heavy duty mailers to ship electronics, books, cosmetics and heavier items of clothing – including things like bags and belts that would perforate or notch a standard mailer.

Learn more about Ecommerce packaging


Important documents, like legal paperwork and confidential information, can be shipped securely in heavy duty polythene bags. They can be made fully opaque, and offer a little extra protection from curious eyes.

Car parts

Heavy duty mailing bags are strong enough to use for non-fragile auto parts, like gaskets and hoses – things that would probably deform a standard light duty mailing bag.

Read more: Polythene In The Automotive Industry


Quick shipments of critical medical supplies and healthcare products can be sent in heavy duty mailers, reducing contamination risks and allowing for faster modes of transport. 

Read more about medical packaging

We supply strong mailing bags in a huge range of sizes, to cater for just about any product. If you’re looking for a custom designed mailing bag, we’ll help you find the balance between protection, cost and convenience – to suit your businesses and your customers.

Get custom heavy duty polythene mailing bags

See our range of strong mailing bags, made of heavy duty polythene. Get professional packaging solutions, designed to your exact requirements. Get a quote now, or call us on 01773 820415.