Grey mailing bags are one of the easiest ways to post parcels in the UK. They are strong, light and waterproof, and they give a smart, professional look. This guide explains everything you need to know before you choose your bags, from sizes and film thickness to Royal Mail categories, price tiers and bulk buying tips.
It is written for busy online sellers, small shops and warehouses that want simple, clear advice on which grey mailing bags and mailing bags are best for their parcels.
Quick Summary
- Grey mailing bags are strong, discreet and light, which helps reduce postage costs.
- They are ideal for clothing, textiles, books, boxed goods and general eCommerce orders.
- Many sizes can fit Royal Mail Small Parcel when packed correctly.
- The mixed size pack is a great way to test which sizes fit your products.
- Bulk and wholesale packs offer the lowest cost per bag for regular shippers.
What Are Grey Mailing Bags?
Grey mailing bags are plastic postage bags made from strong polythene film. They are used to send parcels through Royal Mail and couriers. The grey outer layer hides what is inside and gives a clean, neutral finish that suits almost any brand.
Most grey mailing bags in the Mr Bags mailing bags range are made with co-extruded film. This means several thin layers are joined together to create a tough, tear-resistant bag without adding extra weight.
Main Benefits of Grey Mailing Bags
Lightweight
The light film keeps parcel weight down, so you can stay in lower postage bands and protect your margins.
Tear Resistant
Strong polymer film helps protect against rips during sorting and courier handling, even with heavier soft goods.
Waterproof
Water-resistant film helps shield parcels from rain and surface moisture in transit.
Privacy
The opaque grey colour keeps products private and gives discreet packaging for clothing and personal goods.
Multipurpose
Grey mailing bags work for clothing, books, textiles, small boxed items and many other product types. They are a simple standard for most eCommerce orders.
Key Features at a Glance
Material
Co-extruded LDPE polythene for a good balance of strength and flexibility.
Colour
Solid grey outside with a lighter inner layer for clear label scanning.
Seal
Permanent self-adhesive strip for quick, tamper-evident closure.
Thickness
Commonly 50–70 micron. Thicker film is better for heavy or sharp-edged items.
Finish
Opaque, smooth surface that works well with labels and barcodes.
Use Cases
Clothing, textiles, printed matter, gifts, boxed goods and general eCommerce parcels.
How to Measure Your Product for a Grey Mailing Bag
To pick the right bag, measure the product when it is packed as you plan to ship it. Use this simple method:
- Measure the width: Lay the item flat and measure the widest point across.
- Measure the length: Measure from top to bottom once the item is folded as you will pack it.
- Allow for depth: If the item is thick (like a box or folded jumper), add 5–8 cm to the width.
- Add sealing space: Add at least 5 cm to the length so there is room for the flap and seal.
- Choose the next size up: Do not pick a bag that is tight; this can cause stress on the seal.
As a rough guide, if a folded product measures 24 x 30 cm, a 10 x 14 inch mailing bag is usually a safe choice.
Grey Mailing Bag Size Guide
The table below gives common grey mailing bag sizes and what they suit best. Always check live sizes on the grey mailing bags collection.
| Bag Size (Width x Length) | Typical Use | Notes |
|---|---|---|
| 6 x 9 inch (150 x 230 mm) | Phone cases, cables, cosmetics, small accessories | Letterbox-friendly when packed flat. |
| 9 x 12 inch (230 x 305 mm) | Folded T-shirts, light tops, small books | Popular starter size for clothing brands. |
| 10 x 14 inch (255 x 355 mm) | Jumpers, hoodies, several items together | Ideal for mixed fashion orders. |
| 12 x 16 inch (305 x 405 mm) | Shoe boxes, bulk clothing, soft toys | Good all-round eCommerce size. |
| 14 x 19 inch (355 x 480 mm) | Coats, larger boxed items, textiles | Useful for outerwear and bundles. |
| 17 x 24 inch (430 x 610 mm) | Bedding, pillows, large soft goods | Ideal for courier shipments. |
Try All Sizes with the Grey Mailing Bags Mixed Pack
If you are not sure which size you need, the mixed pack is the easiest place to start. It lets you test several of the most popular sizes in real orders before you commit to full cases.
The Grey Mailing Bags Mixed Pack (120 bags) includes a spread of small, medium and large bags. Many new customers and home sellers choose this first to find their ideal “core” sizes.
What You Get
- A mix of key sizes for clothing, books and soft goods.
- Strong co-extruded film with permanent self-seal strip.
- Smart grey finish for privacy and simple branding.
Who It Suits
- New eCommerce sellers testing sizes.
- Small businesses sending mixed order types.
- People posting gifts and home items during the year.
Once you know which sizes you use most, you can move to bulk packs in the main grey mailing bags range for better value per parcel.
Best-Selling Grey Mailing Bags
Everyday Clothing Orders
9 x 12 inch and 10 x 14 inch are best for T-shirts, tops and hoodies. Many fashion brands use these as their core sizes.
Shoe Boxes and Mixed Orders
12 x 16 inch works well for shoe boxes, bulk clothing and higher-value orders that need a bit more space.
Large Soft Goods
14 x 19 inch and 17 x 24 inch are popular for bedding, pillows and big soft goods shipped by courier.
Royal Mail Size Guide for Grey Mailing Bags
Most sellers want their parcels to fit within Royal Mail size bands. This keeps shipping costs clear and helps with product pricing.
| Grey Mailing Bag Size | Likely Category | Key Limits |
|---|---|---|
| 6 x 9 inch, 9 x 12 inch | Large Letter or Small Parcel | Large Letter depth limit is 2.5 cm. Thicker parcels move to Small Parcel. |
| 10 x 14 inch, 12 x 16 inch | Small Parcel | Max size 45 x 35 x 16 cm including packed thickness. |
| 14 x 19 inch, 17 x 24 inch | Small or Medium Parcel | Check both length and depth once packed. |
This is a general guide only. Always check current Royal Mail rules and test sample parcels before setting flat-rate shipping on your store.
Who Uses Grey Mailing Bags?
- Clothing and fashion brands shipping daily orders.
- eBay and Amazon sellers dispatching mixed parcels.
- Shopify and other web shops sending soft goods and boxes.
- Etsy and craft sellers posting handmade items and supplies.
- Market traders and pop-up shops sending follow-up orders.
- Warehouses and fulfilment centres handling bulk dispatch.
Because they are neutral and discreet, grey mailing bags work well across many industries without clashing with your brand colours.
How Grey Mailing Bags Support Your Brand Image
Grey mailing bags may look simple, but they help your brand in several ways:
- Consistent look: A clean grey outer layer looks neat and professional on every parcel.
- Easy branding: You can add logo stickers, branded inner bags or tissue to build a recognisable look.
- Discreet for buyers: Many customers like parcels that do not draw attention at the doorstep.
- Supports reviews: Strong packaging reduces damage and returns, which helps protect your seller ratings.
Grey Mailing Bags Compared with Other Mailing Options
The table below shows how grey mailing bags compare with other common packaging choices.
| Packaging Type | Protection | Weight | Cost Per Parcel | Best For |
|---|---|---|---|---|
| Grey Mailing Bags | Good for soft and boxed items | Very light | Low, especially in bulk | Clothing, textiles, boxed goods, general eCommerce parcels |
| Coloured Mailing Bags | Similar to grey | Very light | Usually slightly higher | Brands that want bright colours or seasonal looks |
| Bubble Envelopes | Better for small fragile items | Light to medium | Medium | Electronics, cosmetics, small gifts |
| Cardboard Boxes | High, rigid protection | Heavier | Higher | Fragile or premium items, sets and hampers |
| Paper Mailing Bags | Good, but less water-resistant | Medium | Medium to high | Eco-first and plastic-reduced ranges |
Mr Bags vs Other Grey Mailing Bag Suppliers
When choosing a supplier, it is not just about the lowest sticker price. You also need reliable film quality, honest sizing and steady stock.
- Film strength: Bags in the Mr Bags grey mailing bags range are selected for everyday eCommerce use, not ultra-thin film that tears easily.
- Consistent sizing: Clear width and length details help you match products to bags without guesswork.
- UK-based stock: You can top up quickly during busy periods without long delays.
- Clear product pages: Each listing explains sizes, uses and pack types in simple language.
Pros and Cons of Grey Mailing Bags
Pros
- Discreet grey colour that suits almost any brand.
- Lightweight, helping you keep postage costs low.
- Strong self-seal strip that is hard to open without damage.
- Wide size range from letterbox-friendly to large courier sizes.
- Easy to store in bulk in small packing spaces.
- Excellent value, especially in case and wholesale packs.
Cons
- Not padded, so fragile items need extra wrapping or a box.
- Sharp corners and metal parts can pierce the film if not protected.
- Not rigid, so paperwork can bend unless backed with card.
Common Mistakes to Avoid with Grey Mailing Bags
- Using a bag that is too small: This puts stress on seams and seals, increasing the risk of tearing.
- Overfilling the bag: Bulging parcels can fail size checks and cost more to ship.
- Choosing film that is too thin: Very cheap bags may split under the weight of books or dense textiles.
- Ignoring sharp edges: Boxes and items with corners should be wrapped or cushioned before going in the mailing bag.
- Placing the label over the flap: Labels should sit on a flat surface for clean scanning.
How Thick Should Grey Mailing Bags Be?
Thickness is usually expressed in micron. These are simple guidelines:
- 40–50 micron: Light clothing, soft goods and non-heavy items.
- 55–60 micron: Good all-round choice for mixed eCommerce orders.
- 65–70 micron: Heavier, denser or boxed items where extra toughness is needed.
If in doubt, choose the slightly thicker option, especially during peak seasons when parcels move through many hubs.
Packing Tips to Reduce Damage and Returns
- Fold items neatly to make a flat, firm parcel.
- Use an inner clear bag for clothing if you want an extra layer of presentation.
- Pad corners and sharp parts with card or bubble film.
- Do not overfill; leave enough space for the flap to close without strain.
- Press along the seal to make sure the adhesive has full contact.
- Place the label on the flattest side for easy scanning by Royal Mail and couriers.
Eco and Recycling Information
Grey mailing bags are made from plastic film, but there are still ways to reduce their impact:
- Use the smallest size that safely fits each order to cut down on material use.
- Encourage customers to reuse bags for returns or storage where possible.
- Some local recycling points accept clean LDPE film; customers can check local guidance.
- If you run eco or plastic-reduced ranges, you can mix paper mailing bags with grey polythene bags where extra water resistance is needed.
Cost and Value: How Grey Mailing Bags Save Money
Even small savings per order add up over time. Grey mailing bags help in several ways:
- Lower parcel weight compared with cardboard boxes.
- Less storage space in your packing area.
- Fast packing speed, which reduces labour cost per order.
- Bulk pricing when you buy full cases or wholesale packs.
If you save just five pence per order on packaging or postage and ship 5,000 orders a year, that is £250 saved. For many businesses, the saving is much higher.
Wholesale and Bulk Pricing for Grey Mailing Bags
Regular shippers often move from small packs to full cases or wholesale bundles. This gives a better cost per bag and smoother stock planning.
Why Bulk Buying Helps
- Lower cost per bag compared with small top-up packs.
- Less chance of running out of key sizes during busy weeks.
- More predictable packing costs per order.
Price Comparison by Pack Type
| Pack Type | Typical Quantity | Best For | Cost Per Bag |
|---|---|---|---|
| Mixed Pack | Around 120 mixed sizes | New customers testing sizes, home use | Highest per bag, lowest commitment |
| Small Single-Size Pack | Around 100 bags | Low to medium volume sellers | Medium cost per bag |
| Case / Box Quantity | Around 200–500 bags | Growing shops and regular daily orders | Low cost per bag |
| Wholesale / Bulk Case | 1,000+ bags | High-volume sellers, warehouses, fulfilment centres | Lowest cost per bag |
For live prices across all sizes, visit the grey mailing bags collection and the full mailing bags collection.
How to Choose from the Mr Bags Grey Mailing Bag Range
For clothing, start with grey mailing bags for clothing and fashion orders. For heavier or mixed goods, look at strong grey mailing bags for UK shipping in the wider mailing bags collection.
- If you want to test sizes, choose the grey mailing bags mixed pack.
- If you already know your sizes, pick bulk grey mailing bag packs for best value.
- If you send a mix of products, explore both grey poly mailers and other mailing bag colours for branding and seasons.
Grey Mailing Bags for eBay, Amazon and Shopify Sellers
For online sellers, grey mailing bags keep packing simple and fast. You can standardise two or three main sizes for most orders and train staff to use them without confusion.
- eBay: Light parcels help you offer free or low-cost shipping on listings.
- Amazon: Suitable for Merchant Fulfilled orders and some prep work for fulfilment centres.
- Shopify and web shops: Easy to store, easy to label and straightforward to reorder.
When to Use Boxes Instead of Grey Mailing Bags
Grey mailing bags are not the right choice for every item. Use a cardboard box when:
- The product is fragile, such as glass, ceramics or delicate electronics.
- The parcel is very heavy and may tear thin film in transit.
- You want a more premium unboxing experience with printed cartons.
Many sellers use both: a retail box or inner carton for presentation and protection, and a grey mailing bag on the outside for privacy and water resistance.
Our Service Promise
- Fast dispatch on in-stock grey mailing bags.
- Clear product details with real size information.
- Support for small, growing and high-volume sellers.
- UK-based customer service ready to help with size and product queries.
Helpful Downloads
You can offer your team simple tools so they pick the right packaging every time. Suggested downloads include:
Related Packaging You May Also Need
If you like grey mailing bags, you may also find these colours and packing supplies useful for your orders:
- Blue mailing bags for colourful ecommerce parcels
- Green mailing bags for eco-led and seasonal campaigns
- Pink mailing bags for gifts, boutiques and online fashion
- Purple mailing bags for bold, branded parcel packaging
- Packaging tape for sealing boxes and mailing bags
- Cardboard boxes for heavy, fragile or premium items
- Labels and stickers for clear, professional parcel addressing
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