Grey Mailing Bags

Features & Benefits of Grey Mailing Bags

• Grey polythene mailing bags
• Approximately 50 microns thick
• Equivalent to approximately 200 gauge
• Lightweight construction helps reduce unnecessary postal weight
• Opaque material helps conceal the contents
• Permanent peel-and-seal adhesive closure
• Quick to pack without additional packaging tape
• Tamper-evident closure shows visible signs of opening
• Water-resistant polythene helps protect against light rain and splashes
• Flexible material adapts around clothing and other soft products
• Suitable for posting non-fragile retail and e-commerce orders
• Smooth outer surface accepts many courier and address labels
• Grey exterior provides a clean, professional appearance
• Space-saving alternative to rigid postal cartons for suitable products
• Available in a range of sizes
• Measurements are shown as width × height
• Suitable for online retailers, warehouses, fulfilment centres and mail-order businesses
• Clean and uncontaminated bags may suit specialist flexible-plastic recycling services
• Free UK delivery

Common Uses

Our Grey Mailing Bags are suitable for posting and protecting:

• Clothing
• T-shirts
• Trousers
• Knitwear
• Soft furnishings
• Bedding
• Towels
• Fabric products
• Accessories
• Shoes already protected inside a suitable inner container
• Books with additional protective wrapping
• Catalogues
• Documents
• Printed materials
• Textile samples
• Craft supplies
• Non-fragile retail products
• Replacement parts without sharp edges
• Sealed stationery products
• Promotional materials
• Subscription products
• E-commerce orders
• Mail-order purchases
• Customer returns

Always select a size and specification that comfortably accommodates the complete dimensions, shape and weight of the intended contents.

Grey Mailing Bags

Our Grey Mailing Bags provide a lightweight and practical packaging solution for e-commerce businesses, online retailers, warehouses, fulfilment operations and mail-order companies.

The opaque grey polythene helps conceal the contents during storage and delivery. This makes the bags particularly suitable for clothing, textiles, accessories and other non-fragile products that do not require the rigid protection of a cardboard postal carton.

Each bag includes a peel-and-seal closure. Simply remove the release strip, fold the sealing lip over the opening and press the adhesive firmly into place. This permanent closure eliminates the need to apply separate packaging tape under normal conditions.

The flexible polythene adapts around soft and irregularly shaped products, helping businesses avoid sending unnecessary empty space through the parcel network. Additionally, the lightweight material adds relatively little weight to the completed parcel.

These grey mailing bags are approximately 50 microns thick, equivalent to approximately 200 gauge. This thickness provides practical everyday protection for suitable non-fragile postal products.

Grey Mailing Bags Size and Specification

The general product specification is:

• Measurement order: width × height
• Material: polythene
• Colour: grey
• Appearance: opaque
• Approximate thickness: 50 microns
• Approximate gauge: 200 gauge
• Closure: permanent peel-and-seal adhesive strip
• Opening: top opening beneath the sealing lip
• Construction: flexible mailing bag
• Protection: water-resistant under normal postal conditions
• Padding: none
• Handles: none
• Suitable for: non-fragile postal and courier products
• Available sizes: select the required width × height option

The dimensions and film thickness are nominal manufacturing measurements. Therefore, small production tolerances may apply.

The sealing lip is normally positioned above the usable body of the bag. Unless the selected product specification states otherwise, the stated height should be treated as the usable body height rather than including the sealing flap.

Understanding Width × Height Measurements

We display the dimensions of these bags as width × height.

The first measurement represents the width across the bag while it lies flat.

The second measurement represents the usable height from the sealed bottom to the opening beneath the sealing lip.

For example, a mailing bag described as 300mm × 400mm measures approximately 300mm across its width and 400mm along its usable body height.

The peel-and-seal lip extends above the opening and folds down after filling. Unless expressly stated in the selected specification, do not include this lip when calculating the usable internal height.

Because the bag is manufactured from flexible polythene, bulky products use part of the available width and height as the material forms around them. Therefore, a rigid item measuring exactly the same as the flat dimensions will not necessarily fit.

Always measure the complete product at its widest and tallest points. Then allow additional clearance for the thickness and depth of the contents.

Approximately 50-Micron Polythene

These grey mailing bags have an approximate film thickness of 50 microns, commonly expressed as approximately 200 gauge.

The material provides a practical balance between flexibility, postal protection and parcel weight. It suits many everyday retail products that need an outer mailing layer but do not require cushioning or rigid structural protection.

However, micron thickness alone does not determine the complete strength or carrying capacity of a mailing bag. Performance also depends on:

• The formulation of the polythene
• Bag dimensions
• Weight of the contents
• Shape of the products
• Presence of sharp edges
• Distribution of the load
• Strength of the seams
• Quality of the adhesive closure
• Packing method
• Handling during transit
• Temperature and storage conditions

A product may fit inside the bag while still being too heavy, sharp or rigid for the material. Therefore, assess the complete application rather than relying on thickness alone.

If your products are particularly heavy, pointed, valuable or fragile, use a stronger or more protective packaging system.

Opaque Grey Material

The grey exterior helps conceal the products inside the mailing bag.

This provides a more discreet appearance than completely transparent packaging and prevents the contents from being immediately identifiable during routine handling.

The neutral grey colour also gives parcels a clean and professional appearance. It suits businesses across fashion, retail, fulfilment, manufacturing and general e-commerce.

However, the material should not be treated as a security product. Strong light, stretching, damage or very dark and distinctive contents may affect the level of concealment.

Where complete confidentiality or enhanced security is essential, use additional internal packaging and an appropriate tracked delivery service.

The precise shade of grey and surface finish may vary slightly between production batches.

Permanent Peel-and-Seal Closure

Each mailing bag includes a self-adhesive sealing strip protected by a removable release liner.

To close the bag:

1. Place the product completely inside.
2. Smooth out excessive trapped air without damaging the contents.
3. Make sure the sealing area is clean and dry.
4. Remove the release strip.
5. Fold the adhesive lip evenly over the opening.
6. Press firmly across the complete width of the seal.
7. Check that the entire opening has closed correctly.

Once applied, the permanent adhesive creates a tamper-evident closure. Opening the bag will normally damage or distort the polythene, making it difficult to reseal without visible evidence.

Do not remove the release strip until the contents and delivery information have been checked. The adhesive cannot normally be repositioned after it has made firm contact with the bag.

Dust, moisture, grease, fibres and very low temperatures may reduce adhesive performance. Store and pack the bags in a suitable indoor environment.

Tamper-Evident Postal Packaging

The permanent closure provides visible evidence if somebody opens the bag after sealing.

Unlike a reusable grip-seal closure, the adhesive strip is designed for one-time application. The recipient will normally need to tear or cut the bag to access the contents.

This can help businesses identify interference during the delivery process. However, the bags are tamper-evident rather than tamper-proof.

A determined person may still cut, puncture or otherwise damage the polythene. Therefore, valuable or sensitive items may require additional security packaging, tracking, insurance or signed delivery.

Inspect the finished parcel before dispatch and confirm that the seam, body and adhesive closure remain intact.

Water-Resistant Outer Packaging

Polythene provides useful resistance to light rain, splashes and short periods of exposure to damp delivery conditions.

This can help protect clothing, textiles, catalogues and other suitable products from everyday moisture encountered during transport.

However, the bags are not designed for:

• Complete immersion
• Prolonged outdoor storage
• Flooding
• Pressurised water
• Leaking liquids
• Extreme weather exposure
• Guaranteed waterproof containment

Water may enter through an incomplete seal, puncture, damaged seam or opening created during handling.

Products that could be damaged by moisture should also have suitable internal protection. For example, important documents, electrical products and moisture-sensitive textiles may require an additional sealed inner bag.

Lightweight Postal Protection

Grey mailing bags add relatively little weight compared with many rigid packaging materials.

This can be beneficial when delivery prices depend on the parcel’s total weight or dimensions. The flexible construction also reduces unnecessary empty space around soft products.

These bags are particularly useful for clothing and textiles because the material can follow the shape of the contents.

Nevertheless, postal charges depend on the completed parcel rather than the empty bag. Always check the final packed dimensions and weight against the requirements of your chosen postal or courier service.

Do not compress products so tightly that they place excessive pressure on the seams or closure.

Choosing the Correct Grey Mailing Bags Size

Measure the product in the arrangement in which you intend to send it.

For soft items such as clothing, fold the product neatly and measure its widest, highest and thickest points. When sending several items together, measure the combined parcel rather than each item separately.

Allow additional space for:

• Product thickness
• Protective inner wrapping
• Folding the sealing lip
• Removing trapped air
• Variations in product size
• Easy insertion without stretching
• Delivery documents placed inside
• Additional protective materials

Avoid choosing a bag that only just matches the width and height of the product. The contents need enough room to pass through the opening and sit below the adhesive sealing area.

An oversized bag can create excess loose material, while an undersized bag may stretch, split or prevent the closure from sealing correctly.

Where your product sits close to the selected dimensions, request a sample and complete a packing test before ordering for regular use.

Packing Clothing and Textiles

Grey mailing bags work particularly well for soft textile products.

Fold the garment or textile neatly and place it inside a suitable inner bag where additional presentation, hygiene or moisture protection is required.

Slide the product into the mailing bag without forcing it against the side seams. Keep the contents below the adhesive area and remove excessive air carefully.

Do not sit, stand or place heavy objects on the parcel to force air out. Excessive pressure may damage the product, seams or polythene.

For premium clothing, consider adding tissue paper, a garment bag or another suitable inner layer before sealing the outer mailing bag.

Suitable for E-Commerce and Fulfilment

These mailing bags provide an efficient packing option for businesses processing regular postal and courier orders.

Potential users include:

• Online fashion retailers
• Clothing manufacturers
• Marketplace sellers
• Fulfilment centres
• Distribution warehouses
• Subscription businesses
• Independent boutiques
• Shoe and accessory retailers
• Textile suppliers
• Print businesses
• Craft retailers
• Promotional-product suppliers
• Mail-order companies
• Charity shops
• Customer-service departments

The peel-and-seal closure supports a straightforward packing process, while the smooth exterior provides space for compatible shipping labels.

Businesses should test the bags with their packing equipment, labels, printers and courier systems before introducing them into a high-volume fulfilment process.

Applying Address and Courier Labels

Apply the delivery label to a clean, dry and relatively flat section of the bag.

Smooth the surface before attaching the label and press firmly around every edge. Avoid placing labels across:

• The bag opening
• The adhesive sealing area
• Side or bottom seams
• Deep creases
• Loose folds
• Areas stretched tightly around the contents

Flexible polythene can bend and crease during handling. Therefore, use labels and adhesives designed for plastic postal packaging.

Make sure the address, postcode, barcode and tracking information remain clear and unobstructed. Where required, cover or remove any previous labels before reusing a clean bag.

Test your chosen courier labels before using them across regular orders, particularly when parcels will encounter cold, damp or dusty environments.

Grey Mailing Bags Are Not Padded

These bags do not contain bubble lining, foam, paper cushioning or rigid reinforcement.

They provide an outer layer for suitable products but do not protect fragile items against crushing, bending, vibration or impact.

Do not rely on an unpadded mailing bag alone when posting:

• Glass
• Ceramics
• Electronics
• Delicate jewellery
• Fragile ornaments
• Easily bent documents
• Sharp components
• Liquids
• Crush-sensitive products
• Valuable items requiring rigid protection

Use suitable internal cushioning and a strong postal carton where the product requires impact or crush protection.

If a rigid item is placed inside a mailing bag, protect every corner and edge so it cannot puncture the polythene.

Products These Grey Mailing Bags Should Not Contain

Do not use these bags as the only packaging for:

• Exposed blades
• Needles
• Sharp metal parts
• Broken glass
• Unprotected pointed objects
• Hot products
• Hot ashes or embers
• Free-flowing liquids
• Leaking containers
• Corrosive chemicals
• Solvents
• Clinical or infectious waste
• Hazardous substances
• Batteries requiring regulated packaging
• Pressurised containers
• Dangerous goods
• Products requiring UN-approved packaging
• Fragile goods without suitable protection
• Extremely heavy components
• Items that could cut through the film

Select specialist packaging whenever the contents present a sharp, hazardous, liquid, temperature or transport risk.

How to Pack a Grey Mailing Bags

Before packing, inspect the bag for punctures, split seams, contamination or damage to the adhesive strip.

Place the empty bag on a clean and dry packing surface. Prepare the product and any inner protection before removing the release liner.

Insert the contents carefully and make sure no sharp corners press directly against the polythene. Distribute the weight evenly and keep the product below the bag opening.

Remove excessive air gently. Then check the order, delivery address and contents before exposing the adhesive.

Peel away the release strip without touching the adhesive unnecessarily. Fold the sealing flap over in a straight line and press firmly from one side to the other.

Finally, apply the delivery label to a smooth, visible section and inspect the completed parcel before dispatch.

Customer Returns

A permanent peel-and-seal mailing bag will normally need to be torn or cut open by the recipient.

Therefore, the original bag may not remain suitable for returning an item unless the selected design includes a separate return strip or another dedicated resealing feature.

Where returns are common, businesses may wish to:

• Include a separate return mailing bag
• Choose a design with a second adhesive strip
• Provide alternative return-packaging instructions
• Ask customers to use suitable secure outer packaging
• Include a printed return label where appropriate

Do not describe the bag as reusable for customer returns unless the selected product specification confirms an additional return seal.

Storage Recommendations

Store unused grey mailing bags in their original protective packaging in a clean, dry indoor area.

Keep them away from:

• Direct sunlight
• Excessive heat
• Naked flames
• Damp conditions
• Dust
• Grease
• Solvents
• Sharp objects
• Heavy items that could crease the bags
• Extreme changes in temperature

Prolonged heat or sunlight may affect the polythene and adhesive performance.

Allow cold bags to return to normal room temperature before sealing. Very low temperatures can make flexible film less pliable and may reduce the initial bond of some adhesives.

Rotate stock so older bags are used first.

Why Choose Our Grey Mailing Bags?

Our Grey Mailing Bags combine opaque presentation, lightweight polythene construction and a convenient permanent sealing strip.

The grey material helps conceal the contents, while the flexible body adapts around clothing, textiles and other suitable non-fragile products.

Their approximate 50-micron / 200-gauge thickness provides practical everyday protection without adding unnecessary weight or bulk to the parcel.

Meanwhile, the peel-and-seal closure enables quick packing without separate packaging tape. The smooth outer surface also provides a suitable area for compatible courier and address labels.

A choice of width × height sizes allows businesses to select an option that suits their products more closely and reduces unnecessary loose material.

What Are Grey Mailing Bags Also Known As?

People may also refer to these products as:

• Grey postal bags
• Grey postage bags
• Grey mailing sacks
• Grey parcel bags
• Polythene mailing bags
• Plastic mailing bags
• Plastic postal bags
• Poly mailers
• Courier bags
• E-commerce mailing bags
• Self-seal mailing bags
• Peel-and-seal postal bags
• Opaque postal bags
• Tamper-evident mailing bags
• Clothing postage bags
• Online retail mailing bags
• Lightweight parcel bags
• Grey shipping bags
• 50-micron mailing bags
• 200-gauge mailing bags

Although people often use these names interchangeably, mailing bags can differ in dimensions, thickness, recycled content, colour, opacity, seam construction and adhesive configuration.

Always check the selected width × height measurement and complete product specification before ordering.

Food Contact Information

These mailing bags are intended to provide outer postal packaging.

Do not place unpackaged food directly inside the bags unless the product specification and supporting documentation explicitly confirm direct food-contact suitability.

Food products should remain inside suitable primary packaging that prevents direct contact with the mailing bag.

Hot food, grease, oils, condensation and leaking containers may affect the polythene, adhesive closure, delivery label and other products within the parcel.

If you require confirmation for a food-related application or need supporting documentation, please email sales@expresspackaging.co.uk before ordering.

PPWR Compliance Information

Regulation (EU) 2025/40 on Packaging and Packaging Waste, commonly known as the PPWR, applies to packaging placed on the EU market.

We can provide available product specifications and supporting information to help customers complete their compliance assessments. However, polythene construction, low packaging weight or potential recyclability alone does not confirm full PPWR compliance.

The responsible economic operator must assess the product and its intended use against all applicable requirements, including packaging minimisation, substances of concern, material composition, recycled content, recyclability, labelling and technical documentation.

Do not claim that these mailing bags contain a particular percentage of recycled material unless the current specification and supporting documentation confirm that percentage.

Customers intending to place these products on the EU market should email sales@expresspackaging.co.uk to request the latest available documentation and confirm suitability before making a recycled-content, recyclability or PPWR compliance claim.

Material and Responsible Disposal

These mailing bags use flexible polythene construction and include an adhesive sealing strip.

Clean and uncontaminated polythene film may suit a specialist flexible-plastic recycling service, depending on the collection facilities available in your area.

However, many household kerbside recycling services do not accept plastic bags or flexible films. Delivery labels, adhesive residue, contamination and attached materials may also affect recycling suitability.

Before disposal:

• Remove the contents completely
• Remove paper delivery documents where practical
• Check local recycling instructions
• Separate incompatible materials where possible
• Keep contaminated bags out of clean recycling streams
• Follow the guidance of your commercial waste contractor or local authority

Where a bag remains clean and undamaged, consider whether it can be reused for a suitable non-postal storage purpose before disposal. Do not reuse a damaged mailing bag for sending another parcel.

Important Safety Information

Keep unused and used mailing bags away from babies and young children because flexible plastic can present a suffocation risk.

Never use the bags as toys, clothing, bedding or protective covers for people.

Store the bags away from direct heat and naked flames. Polythene can soften, melt or burn when exposed to high temperatures.

Do not place hot products, ashes, embers or heated components inside the bags.

Protect the material from blades, broken glass, sharp corners and abrasive surfaces. Additionally, do not overload the bags or use them for contents that exceed the strength of the material, seams or adhesive closure.

Inspect the parcel before dispatch. If the bag is punctured, overstretched or incorrectly sealed, transfer the contents into a new mailing bag or a more suitable form of packaging.

Always comply with the packaging, labelling and transport rules that apply to the intended contents and delivery service.

Sample Requests

To request a sample, please email sales@expresspackaging.co.uk or call 0121 622 2347.

A small charge applies to sample bags wider than 600mm. Our sales team will confirm any applicable charge and delivery arrangements before sending the sample.

Illustration Only

Clothing, accessories, documents, labels and other products shown in our images demonstrate potential applications only and are not included with the Grey Mailing Bags.

Products vary in width, height, depth, shape and weight. Therefore, measure the complete packed item carefully and allow sufficient clearance before selecting a mailing bag.

Product photographs provide a general representation of the grey material. Lighting, reflections and screen settings may affect how the colour and surface finish appear.