Grey Mailing Bags 21×24" (533×610 mm) – Self-Seal Recycled Postal Bags
Grey Mailing Bags 21×24" (533×610 mm) – Self-Seal Recycled Postal Bags
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Grey Mailing Bags 21×24" (533×610 mm) – extra-large capacity, fast to pack
Grey mailing bags 21×24" (533×610 mm) give generous room for bedding sets, pillows, bulk textiles and larger boxed goods while keeping parcels lightweight. Made from tough 60-micron recycled LDPE, they’re moisture-proof (water-resistant), opaque for privacy, and close in seconds with a self-seal strip.
Need a different fit? See all sizes or browse the full Mailing Bags range.
Why this 21×24" size?
When 17×24" starts to strain, 21×24" adds height for bulkier apparel bundles, duvet covers, throws and mid-size retail boxes—without jumping straight to heavy cartons. Need more width rather than height? Try 20×26" (wider, slightly shorter).
Real use examples
- Textiles & home: bedding sets, pillows, throws, towel bundles, large cushion covers.
- Apparel: coats, knitwear bundles, multi-item clothing stacks.
- Boxed goods: mid-to-large retail boxes and gift sets with inner wrap.
Fit & packing guidance
- Best fit: bedding/textiles, stacked apparel, bigger boxed kits.
- Need more width? Use 20×26".
- Need less bulk? Step down to 17×24" for a neater seal and lower postage.
- Corner care: pad sharp inner-box edges to reduce punctures.
- Press out air: flatten before sealing so labels sit flat and sacks/totes stack cleanly.
Key benefits
- Self-seal, tamper-evident closure for rapid packing.
- 60-micron co-extruded film helps resist tears, splits and scuffs.
- Moisture-proof / water-resistant outer for wet routes.
- Opaque grey for privacy and a clean, uniform look.
- Recyclable LDPE — remove the glue strip before recycling.
Specifications
| Spec | Value |
|---|---|
| Size (inches) | 21 × 24" |
| Size (mm) | 533 × 610 mm |
| Thickness | 60 µm |
| Material | LDPE (Low-Density Polyethylene), recycled |
| Closure | Peel-and-seal, tamper-evident |
| Colour | Grey, opaque |
| Water protection | Moisture-proof / water-resistant |
| Recyclability | Recyclable – remove glue strip before recycling |
Eco & Materials
Material: 100% recycled LDPE (resin code 4), co-extruded for strength and opacity. Recyclable in many UK schemes — please remove the adhesive strip first. Not biodegradable or compostable.
Strength & Protection
60-micron film is puncture- and tear-resistant and moisture-proof. The self-seal, tamper-evident adhesive forms a permanent bond once pressed.
Storage & Performance
Store at 13–21 °C and out of direct heat/sunlight. Let cold stock acclimatise before use to maintain adhesive performance.
Lightweight = Lower Postage
Recycled LDPE mailers are exceptionally lightweight, helping you keep parcels in lower weight bands versus boxes.
Size comparison (choose the right bag)
| Size | Inches | Millimetres | Typical fit |
|---|---|---|---|
| Step down | 17 × 24" | 432 × 610 mm | Bedding sets, bulky textiles, larger kits |
| This page | 21 × 24" | 533 × 610 mm | Pillows, throws, multi-item apparel, bigger boxes |
| Wider option | 20 × 26" | 508 × 660 mm | Wider boxed goods, large textiles |
| Step up | 24 × 36" | 610 × 914 mm | Very large textiles and retail boxes |
Packing tips
- Use a light inner sleeve for dusty items or sharp corners.
- Fold textiles flat; avoid hard creases that create sharp edges.
- Apply labels on a smooth, clean area; press firmly for reliable scanning.
- Add invoices/returns in a clear document wallet outside the bag.
Build a complete packing setup
Team your grey mailing bags 21×24" with packaging tape, document wallets, and cardboard boxes. Explore all sizes in the Mailing Bags collection.
Royal Mail 24 Tracked
Dispatched same day if ordered before 5 pm Monday to Friday. Please allow up to 1-2 days for delivery.
£1.99
DPD Next Day
Dispatched same day if ordered before 3 pm Monday to Thursday. Not available to Scottish Highlands & Islands.
£4.99
Free on orders over £100