Polythene Mailers - Grey 250G
No3 Grey Opaque Poly Mailers — Secure, Professional Postal Bags
These grey opaque polythene mailers are designed for fast, reliable despatch of non-fragile items where privacy, weather resistance and efficient packing matter. The opaque grey film helps conceal contents in transit, while the lightweight construction keeps postage costs down compared with boxes. A peel-and-seal closure supports quick packing at the bench, and the tough polythene film helps protect goods from moisture and handling during courier and mail networks.
This product listing may cover multiple pack options and related variants within the same range. Please select the option that best suits your operation and order volume.
Key Features
Opaque grey film for discretion
The grey, non-see-through material helps keep contents private during delivery and reduces the visibility of branded inner packaging.
Lightweight protection
Polythene mailers add minimal weight while providing a protective outer layer against rain, splashes and general transit grime.
Peel-and-seal closure for speed
A self-seal adhesive strip supports consistent, repeatable sealing without tape—ideal for busy packing stations.
Tough polythene construction
The film is specified at 55 micron, offering a practical balance of durability and flexibility for everyday fulfilment.
Space-efficient storage
Supplied flat, poly mailers take up far less space than cartons, helping keep pick/pack areas tidy and efficient.
Clean, professional presentation
A neat grey outer bag gives parcels a uniform look—useful for marketplaces, retail despatch and trade shipments.
- Opaque grey polythene mailer for discreet shipping
- 55 micron film specification
- Self-seal / peel-and-seal closure for fast packing
- Moisture-resistant outer layer for transit protection
- Supplied flat to save storage space
Typical Uses
- Clothing and textiles (t-shirts, hoodies, uniforms, soft goods)
- Mail-order and eCommerce fulfilment
- Catalogues, printed materials and non-fragile items
- Returns bags and reverse logistics (where appropriate)
- Trade counters and warehouse despatch for lightweight goods
No3 Grey Opaque Poly Mailers — Full Product Guide
Grey opaque poly mailers are a staple of modern fulfilment because they combine speed, protection and a low cost-per-parcel. They are particularly effective when the item being shipped is not easily crushed and does not require rigid protection. For many businesses, switching from boxes to mailers for suitable products reduces packing time, lowers dimensional weight exposure, and simplifies storage.
Below is a practical guide to help you choose, use and get the best performance from this mailer range.
How It Works
Poly mailers are flexible postal bags made from polythene film. You place the item inside, remove the release liner from the adhesive strip, and fold the flap down to seal. Once sealed, the bag forms a protective outer layer around the contents. The opaque grey film helps prevent the contents from being seen, which can be beneficial for customer privacy and for reducing attention during transit.
For best results, aim to remove excess air before sealing so the parcel stays compact and easier to handle through automated sorting and courier networks.
Materials and Construction
This product is specified as a grey opaque polythene mailer with a 55 micron film. In practical terms, micron is a measure of film thickness; thicker films generally offer improved puncture and tear resistance, while thinner films can be more economical and lighter. A 55 micron mailer is commonly used for everyday shipping of soft goods and general merchandise.
The mailer includes an adhesive peel-and-seal strip on the flap. This supports consistent sealing without additional tape, helping standardise packing quality across teams and shifts.
Privacy and Presentation
Opaque grey mailers are widely used where discretion is important. The non-transparent film helps conceal the contents and any inner packaging. This can be useful for fashion, personal items, subscription shipments, and general eCommerce orders where customers prefer a neutral outer parcel.
Grey also provides a clean, uniform look across shipments, which can help operations that want a consistent despatch appearance across multiple product lines.
Weather Resistance and Transit Protection
Polythene mailers provide a moisture-resistant barrier that helps protect against rain and splashes during last-mile delivery. They also help keep parcels clean when handled in depots, vans and sorting facilities. While mailers are not designed to replace rigid packaging for fragile items, they are an effective outer layer for many non-breakable products.
If you are shipping items that could be damaged by bending or crushing, consider pairing a mailer with internal protection (such as a board-backed envelope, internal carton, or protective wrap) depending on your product requirements.
Floor Type Compatibility (Warehouse & Packing Areas)
Because these mailers are supplied flat and are lightweight, they are easy to store in racking, shelving, or pick-face bins. They work well in typical warehouse and packing environments, including benches, conveyor-fed packing lines and small fulfilment rooms. Keeping mailers in a dispenser or neatly stacked can reduce handling time and improve packing consistency.
Health and Safety
- Adhesive handling: Avoid contact with the adhesive strip where possible to maintain seal performance and reduce skin irritation for sensitive users.
- Cutting tools: If opening returned parcels with blades, use safety cutters and cut away from the body.
- Slip hazards: Loose polythene can be slippery—keep work areas clear of offcuts and packaging waste.
- Suffocation warning: Keep plastic bags away from babies and children.
Ideal Applications and Use Cases
These grey opaque poly mailers are typically chosen for:
- Apparel fulfilment: garments, accessories, soft footwear (where appropriate)
- Retail despatch: marketplace orders and direct-to-consumer shipments
- Printed goods: catalogues and non-fragile printed materials (consider internal stiffeners if needed)
- Warehouse transfers: lightweight items moving between sites or departments
Maintenance, Cleaning and Care
Poly mailers are single-use packaging and do not require maintenance. To keep packing performance consistent:
- Store in a clean, dry area away from direct sunlight and heat sources.
- Keep cartons closed until use to reduce dust contamination on the adhesive strip.
- Rotate stock so older cartons are used first.
Case Study (Operational Example)
Scenario: A small-to-medium eCommerce operation shipping soft goods wanted to reduce packing time and storage space used by cartons.
Approach: They moved suitable SKUs (non-fragile items) to grey opaque poly mailers and standardised a simple packing method: insert item, remove excess air, seal, apply label.
Outcome: Packing became faster and more consistent, storage space improved due to flat-packed mailers, and parcels presented a uniform, discreet appearance. (Results will vary depending on product mix and carrier handling.)
Who Is It For?
- eCommerce brands and marketplace sellers shipping soft goods
- Warehouses and fulfilment centres needing fast, repeatable packing
- Retailers and trade counters despatching lightweight items
- Businesses that want discreet, opaque outer packaging
Colours / Features Available
This listing is for grey opaque polythene mailers. Opaque mailers are commonly selected for privacy and a clean, neutral look. If you require alternative colours or additional features (such as printed warnings or bespoke branding), check the wider mailer range available on the site.
Sizes Available
This product page may represent a range of sizes and pack quantities within the same grey opaque mailer family. Choose the size that comfortably fits your product with enough room to seal without overstuffing. If you are between sizes, selecting the next size up can reduce sealing stress and improve packing speed.
Tip: When sizing a mailer, consider the item’s folded dimensions and thickness. Allow extra space for seams and the flap area so the adhesive can close flat and securely.
Specification Summary
- Type: Grey opaque polythene mailer
- Film thickness: 55 micron
- Closure: Peel-and-seal adhesive flap
- Use: Postal / courier despatch for non-fragile items
If you need help choosing the best size for your products or want to optimise your packing process, share what you’re shipping (dimensions, weight, fragility) and your typical daily order volume, and we can recommend a practical setup.