Custom Polymailers UK: Everything Your Business Needs to Know

For any UK business dispatching orders by post, custom polymailers are one of the most impactful packaging choices you can make. They're lightweight, waterproof, cost-effective — and when they carry your brand, they turn every delivery into a branded moment.

This guide covers what custom polymailers are, the sizes we offer, how the printing works, the unboxing experience they create, and how to order.

What Are Custom Polymailers?

Custom polymailers are sealed mailing bags made from co-extruded polyethylene film. They're designed specifically for e-commerce dispatch — lightweight enough to keep postage costs down, tough enough to survive the UK postal system, and waterproof throughout.

Each bag features a self-adhesive peel-and-seal closure strip at the top, making them quick to pack and secure without tape. Once sealed, they're tamper-evident — your customer will know if the bag has been opened before it reached them.

Your brand — logo, name, artwork — is printed directly onto the front face of the mailer in a single colour. The result is clean, professional, and unmistakably yours.

Sizes Available

We offer custom polymailers in three sizes:

22×36cm — the compact option, suited to small accessories, folded lightweight garments, jewellery, and smaller e-commerce orders. Ideal for keeping postage costs down on smaller items.

29×48cm — the most popular size for single garments, medium clothing items, accessories, flat-packed soft goods, and the majority of e-commerce fashion orders.

40×60cm — for larger shipments: multiple garments, bulkier soft goods, subscription bundles, or anything needing more room. Ideal for fashion brands shipping full outfits, multi-pack orders, or larger accessory items.

All three sizes are available in quantities of 50, 100, and 200, and in both white and black.

Print Specifications

All custom polymailers at The Craftionals are:

• Printed one side, one colour — your logo or artwork on the front face
• Available in white and black — the base colour of the bag
• Artwork format: PDF or JPEG, maximum 10MB

The one-side, one-colour approach is by design. A single bold print on a plain bag creates a clean, confident look — exactly what a great brand statement requires. White print on a black mailer is a particularly popular combination, producing a striking minimal aesthetic that photographs well for social media and consistently impresses customers.

What Makes a Good Polymailer Design?

Bold, clear logos and brand marks work best. Avoid very fine lines or gradients, which can be difficult to reproduce accurately in single-colour print. If you need your artwork adapted for print, our design services team can prepare it for you.

The Unboxing Experience

Packaging has become a significant part of the customer experience — and a custom polymailer is the first thing your customer physically touches when their order arrives.

A plain white or grey generic mailer communicates nothing. A branded mailer — your logo printed cleanly on the front — communicates that the business behind it takes its presentation seriously. It builds brand recall before the customer has even opened the bag.

Why Customers Notice

Research consistently shows that branded packaging increases the likelihood of repeat purchases and social sharing. When a customer photographs their order for Instagram or TikTok, the packaging is in the shot. A bold custom polymailer turns your customers into passive brand ambassadors.

This doesn't require a large budget. With minimum orders from 50 units, custom polymailers are accessible for businesses at the earliest stages of growth — not just established brands with large packaging budgets.

Pairing Polymailers with Inner Packaging

Many growing UK businesses use polymailers as the outer postal layer and add a custom frosted zipper bag inside for the product itself. The polymailer handles the logistics; the frosted bag handles the presentation. Together, they create a genuinely impressive unboxing experience — the kind that gets photographed, shared, and remembered.

Who Uses Custom Polymailers?

E-commerce clothing and fashion brands — the most common use case. Lightweight, branded, and perfectly sized for most garments.

Online retailers of soft goods — accessories, homewares, gifts, stationery, and anything that ships flat or folded.

Subscription box services — when the outer packaging needs to carry the brand confidently before the customer even opens the box.

Businesses scaling from Etsy or local markets — custom polymailers are often the first branded packaging investment a growing business makes, and for good reason.

How to Order Custom Polymailers

1. Submit a Quote Request

Request a free quote specifying your preferred size (29×48cm or 40×60cm), quantity, base colour (white or black), and any notes about your print colour. You can also message us directly via WhatsApp.

2. Send Your Artwork

Supply your logo or artwork as a PDF or JPEG (max 10MB). If your file isn't print-ready, let us know and we can advise on what's needed.

3. Approve Your Free Digital Proof

Within 24–48 hours on weekdays, we'll send a free digital proof showing exactly how your design will appear on the finished mailer. No printing happens until you've approved it.

4. Production and Delivery

Once approved, production takes 8–13 working days. Free UK delivery is included on every order, direct to your door.

Custom Polymailers vs Frosted Zipper Bags

Both are popular at The Craftionals — but they do different jobs.

Polymailers are for dispatching orders. They're sealed, lightweight, and built for the postal journey. Choose polymailers if you're primarily an e-commerce business shipping orders to customers.

Frosted zipper bags are for presenting products. They're resealable, premium-feeling, and designed for in-store, market, or in-parcel presentation. Choose frosted bags if you sell in person, attend events, or want impressive inner packaging.

For businesses growing across both channels — or those who want a premium unboxing experience for online customers — both products work together naturally. Start with polymailers for your postal dispatch and add frosted bags when you're ready to add another layer to your presentation.

---

Ready to order? Get a free quote — we'll respond within 24 hours and have your digital proof ready within 48 hours.