Whether you run an eCommerce store, manage a busy packing room or dispatch occasional mailings, choosing the right postal packaging can make a significant difference to your costs, efficiency and the impression you leave on customers.
This guide covers everything you need to know — from a quick-reference product table through to detailed product breakdowns, a decision matrix, sustainable alternatives, practical tips and frequently asked questions.
Free printable cheat sheet
Download our one-page quick reference to put up in your packing room so staff always have the right answer to hand.
Quick Reference Guide
Not sure where to start? Use the table below to find the right postal packaging product at a glance.
| Product | Best For | Key Benefit | View Product |
| Polythene Mailing Bags | Clothing, soft goods, e-commerce | Lightweight, waterproof, self-seal | View Polythene Mailing Bags |
| Paper Mailing Bags | Eco-conscious dispatch, documents | Recyclable (plain), paper-based, professional look | View Paper Mailing Bags |
| Tuck-in Flap Postal Boxes | General parcels, retail | Easy assembly, neat closure | View Tuck-in Flap Boxes |
| Fold-in Flap Postal Boxes | Compact items, clothing, gifts | Flush edges, compact shape | View Fold-in Flap Boxes |
| Peel & Seal Postal Boxes | High-volume dispatch, e-commerce | No tape needed, fast closure | View Peel & Seal Boxes |
| Foam-Lined Boxes | Fragile / high-value items | Built-in cushioning, professional presentation | View Foam-Lined Boxes |
| Cardboard Book Wraps | Books, media, documents, flat items | Slim profile, adjustable to item depth | View Book Wraps |
| Postal Tubes | Posters, drawings, rolled artwork | Rigid protection for rolled items | View Postal Tubes |
| Postal Tube End Caps | Securing postal tubes | Prevents contents escaping in transit | View End Caps |
| Adhesive Envelopes | Documents, letters, small items | Self-seal, lightweight, cost-effective | View Adhesive Envelopes |
| Adhesive Labels | Addressing, shipping compliance | Peel-and-stick, various sizes | View Adhesive Labels |
| Document Wallets for Parcels | Delivery notes, invoices on parcels | Keeps paperwork visible and dry | View Document Wallets |
Postal Packaging Products Explained
A detailed breakdown of each product type available from Proton Packaging, including key features, typical use cases and when to choose each one.
1. Mailing Bags
Polythene Mailing Bags
The most widely used postal packaging solution for e-commerce and retail dispatch. Made from strong co-extruded polythene, they are lightweight, waterproof and tear-resistant, with a self-seal peel-and-stick closure that eliminates the need for tape.
- Key features: Lightweight, waterproof, self-seal peel strip, multiple sizes and colours
- 30% post-consumer waste (PCW) versions available for Plastic Packaging Tax compliance
Best for: Clothing, soft goods, fashion accessories, books, e-commerce fulfilment
Paper Mailing Bags
Paper mailing bags offer a paper-based alternative to polythene mailing bags. Made from brown kraft paper and popular with eco-conscious businesses. Some versions are available with a bubble-lined interior for added protection.
- Plain paper versions: 100% recyclable and paper-based
- Bubble-lined versions available for added protection — not recyclable
- Available plain or custom printed, with self-seal closure
Best for: Eco-conscious businesses, clothing and lifestyle brands, smaller goods
2. Postage Boxes
For items that need the rigid protection of a cardboard box rather than a flexible bag, Proton Packaging stocks a range of postal box styles to suit different packing operations and item types.
Tuck-in Flap Postal Boxes
Most popular
The most commonly used postal box design. Interlocking flaps at each end fold in to create a neat, secure closure. Strong, easy to assemble and suitable for a wide range of items.
Best for: General retail parcels, e-commerce, books, gifts, mixed product lines
Fold-in Flap Postal Boxes
Side flaps fold inward to create flush edges and a compact, square profile. Particularly useful for clothing, folded items or lighter goods where a snug fit is important.
Best for: Clothing, gifts, folded garments, lightweight products
Peel & Seal Postal Boxes
High-volume favourite
A built-in self-adhesive strip means simply peel, press and go — no tape required. A major advantage in high-volume dispatch operations where every second counts.
Best for: High-volume e-commerce, fast dispatch, subscription boxes
Foam-Lined Boxes
Fragile items
A layer of protective foam bonded to the interior walls and base provides built-in cushioning — no additional bubble wrap or void fill required. Ideal for fragile, high-value or precision items.
Best for: Jewellery, electronics, cosmetics, glass, high-value gifts
Cardboard Book Wraps
Slim, adjustable cardboard wraps designed specifically for flat items such as books, DVDs, catalogues and documents. The fold-and-tuck design conforms to the exact depth of the item — no void fill needed.
Best for: Books, media, printed materials, documents, flat goods
3. Postal Tubes
Postal Tubes
Rigid cardboard cylinders designed for shipping rolled items — posters, prints, architectural drawings, maps, artwork and fabric samples. The strong tube wall protects contents from crushing and bending during transit.
- Rigid protection for rolled items
- Available in a range of diameters and lengths
- Kraft construction — recyclable and lightweight
- Suitable for Royal Mail and courier services
Best for: Posters, prints, drawings, architectural plans, canvas, rolled fabric
4. Envelopes, Labels & Document Wallets
Adhesive Envelopes
Self-seal envelopes in a range of standard sizes with pressure-sensitive peel-and-seal strips for fast closure. A cost-effective solution for documents, small flat items and lightweight correspondence.
Best for: Invoices, letters, documents, small flat items, low-weight mailings
Adhesive Labels
Address and shipping labels suitable for laser and inkjet printers, in a range of sheet sizes and label dimensions. Using correctly sized labels ensures clean, professional addressing and reduces dispatch errors.
Best for: Addressing parcels, returns labels, shipping compliance, product labelling
Document Wallets for Parcels
Clear adhesive pockets that attach to the outside of a parcel, keeping delivery notes, invoices and customs forms visible and protected from moisture — no need to open the parcel to locate paperwork.
Best for: Delivery notes, B2B shipping, international dispatch
Choosing by Item Type
Different items require different postal packaging. Use the scenarios below to match your product to the right solution.
👕 Clothing & Soft Goods
Soft, non-fragile items require minimal packaging — the main priority is waterproofing and secure closure.
- Polythene Mailing Bags — lightweight, waterproof, self-seal
- Fold-in Flap Postal Boxes — where a boxed presentation is preferred
- Custom Printed Mailing Bags — to reinforce brand identity
📚 Books, Flat Media & Documents
Require a snug fit to prevent movement and sufficient rigidity to prevent corner damage and page bending.
- Cardboard Book Wraps — purpose-built, adjustable depth, light and cost-effective
- Tuck-in Flap Postal Boxes — where a standard box format is preferred
- Adhesive Envelopes — for documents and lightweight paperwork only
💎 Fragile & High-Value Items
Need cushioning to absorb shocks during transit. The right combination of outer packaging and interior protection is critical.
- Foam-Lined Postal Boxes — all-in-one; built-in protection with no extra packing required
- Tuck-in Flap Boxes + Bubblewrap — for lighter fragile items
- Tuck-in Flap Boxes + Foam Rolls — for items with delicate surfaces
🖼 Posters, Prints & Rolled Items
Cannot be folded and require a rigid outer to prevent bending. Postal tubes are the established solution.
- Postal Tubes — select a diameter slightly larger than the rolled item
- Postal Tube End Caps — always use on both ends
📦 High-Volume E-Commerce
Speed of packing is as important as protection. Every second saved per parcel has a measurable impact on labour costs.
- Peel & Seal Postal Boxes — eliminates the tape step entirely
- Polythene Mailing Bags — self-seal, no tape gun needed
- Adhesive Labels — pre-cut labels speed up address application
- Document Wallets — attach paperwork to the outside
Which Postal Packaging Should I Use?
Use the matrix below to quickly identify the right product for what you are sending.
| You are sending… | Recommended product | Why | View |
| Clothing & soft goods | Polythene Mailing Bags | Lightweight, flexible, waterproof | View Polythene Mailing Bags |
| Books, DVDs, flat media | Cardboard Book Wraps | Slim profile, adjusts to item depth | View Book Wraps |
| Posters, blueprints, artwork | Postal Tubes + End Caps | Rigid protection for rolled items | View Postal Tubes |
| Fragile or high-value items | Foam-Lined Postal Boxes | Built-in cushioning, no extra packaging needed | View Foam-Lined Boxes |
| General retail parcels | Tuck-in Flap Postal Boxes | Versatile, neat closure, easy to assemble | View Tuck-in Flap Boxes |
| High-volume e-commerce | Peel & Seal Postal Boxes | Eliminates tape step, speeds up packing | View Peel & Seal Boxes |
| Documents & paperwork only | Adhesive Envelopes | Lightweight, self-seal, cost-effective | View Adhesive Envelopes |
| Eco-conscious parcels | Paper Mailing Bags or Book Wraps | Paper-based, recyclable alternatives (plain bags only) | View Paper Mailing Bags |
Sustainable Postal Packaging Options
With the UK Plastic Packaging Tax now in force and growing customer demand for eco-friendly packaging, many businesses are reviewing their postal packaging materials. Proton Packaging offers several alternatives.
♻ Paper Mailing Bags
A fully paper-based, recyclable alternative to polythene mailing bags. Plain versions are 100% recyclable; bubble-lined versions are not recyclable due to mixed-material construction.
♻ 30% PCW Polythene Bags
Maintains the performance of standard polythene mailing bags while meeting Plastic Packaging Tax requirements — manufactured with 30% post-consumer waste content, available in a range of sizes and gauges.
♻ Cardboard Book Wraps & Postal Boxes
Made from recyclable corrugated cardboard — recycle with standard cardboard waste. Right-sizing your box also reduces material use and courier costs.
♻ Gummed Kraft Paper Tape for Sealing
A strong, tamper-evident, fully recyclable seal that bonds directly into cardboard fibres — one of the most sustainable tape options available. See the Packing Tape Guide for more information.
Tips & Best Practice
In addition to choosing the right packaging, there are important considerations around right-sizing, sealing and storage. Getting these right reduces damage, costs and waste.
Right-Sizing Your Packaging
One of the most common and costly mistakes is using a box or bag that is too large for the item being sent. Oversized packaging results in:
- Higher courier charges — most couriers price by dimensional weight above certain thresholds
- More void fill required — increasing material costs
- Greater risk of items moving and being damaged in transit
- Unnecessary packaging waste
Sealing Postal Boxes Correctly
A poorly sealed box is one of the most common causes of transit damage. Follow the H-taping method for maximum security:
- Apply tape along the full length of the central seam
- Apply two additional strips across both ends of the seam (forming an H shape)
- Press firmly across the full length of each tape strip to activate the adhesive
For guidance on which tape to use, see the Packing Tape Guide.
Labelling
Apply address labels to the largest flat face of the parcel, away from seams and joins. Press all edges down fully to prevent corners lifting and jamming in sorting machinery.
Protecting Fragile Items
- Wrap fragile items individually with bubble wrap or foam before placing in the box
- Fill all remaining void space with packing peanuts, air pillows or crumpled kraft paper
- The item should not move when the closed box is shaken
- For very high-value items, consider double-boxing
Storing Postal Packaging
Store postal boxes flat in a dry environment — humidity weakens corrugated cardboard and reduces stack strength. Store polythene mailing bags in a sealed outer or on a clean shelf away from sharp objects.
Frequently Asked Questions About Postal Packaging
What is the best postal packaging for clothing?
Polythene mailing bags are the most widely used solution for clothing. They are lightweight, waterproof and self-sealing, making them fast and cost-effective for e-commerce clothing dispatch. For a more premium presentation, fold-in flap postal boxes offer a neat boxed format without added bulk.
What is the difference between tuck-in flap and fold-in flap postal boxes?
Tuck-in flap boxes have interlocking flaps at each end that tuck in to seal — the standard general-purpose choice. Fold-in flap boxes have side flaps that fold inward for a flush, compact profile, making them better suited to thinner or lighter items such as clothing and folded garments.
Do I need tape for a peel and seal postal box?
No. Peel and seal postal boxes have a built-in self-adhesive strip — simply peel the liner, press the lid down and the box is sealed. No tape is required, which makes them significantly faster in high-volume dispatch environments.
What size postal tube do I need?
Choose a tube with an internal diameter slightly larger than your rolled item, and a length that allows the item to sit fully inside with end caps in place. A few millimetres of clearance is ideal. Avoid tubes significantly larger than the item, as excess space allows the roll to shift during transit.
Are polythene mailing bags recyclable?
Standard polythene mailing bags are technically recyclable, but are not widely accepted in kerbside collections. Many retailers and supermarkets operate carrier bag recycling points that accept them. For a more easily recyclable option, plain paper mailing bags or 30% PCW polythene bags are available from Proton Packaging. Note that bubble-lined paper mailing bags are not recyclable due to their mixed-material construction.
What is the cheapest way to send parcels in the UK?
Courier pricing is based on parcel weight and dimensions. Using right-sized packaging — and mailing bags rather than boxes wherever possible — reduces both the dimensional weight and the physical weight of parcels, helping more items qualify for lower courier price brackets.
Can I use bubble wrap inside postal boxes?
Yes — wrapping fragile items in bubble wrap before placing them inside a postal box is best practice. For items that are frequently fragile or high-value, foam-lined postal boxes provide built-in cushioning so you do not need to add bubble wrap separately. See the Cushioning & Protective Packaging Guide for more detail.
What is a document wallet for parcels?
A document wallet is a transparent self-adhesive pocket that sticks to the outside of a parcel. It holds delivery notes, invoices, returns slips or customs forms securely on the outside, keeping them dry and visible without the need to open the parcel.
Browse the Full Postal Packaging Range
Everything you need for professional, cost-effective mailing — in stock and ready to order.