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Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags

Size Guide

Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags
Product Title: Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags
Lowercase: grey mailing bags 14×21" (356×533 mm) – self-seal recycled postal bags
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14x21 Inch Grey Plastic Postage Bags - Mailing Bags for Parcels

Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags

Size Guide

Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags
Product Title: Grey Mailing Bags 14×21" (356×533 mm) – Self-Seal Recycled Postal Bags
Lowercase: grey mailing bags 14×21" (356×533 mm) – self-seal recycled postal bags
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Show Cardboard Box: false
Regular price £9.00
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Product Description

Grey Mailing Bags 14×21" (356×533 mm) – reliable space for jackets & textiles

Grey mailing bags 14×21" (356×533 mm) give extra room for jackets, thicker knits, textiles and larger A4 bundles while keeping parcels lightweight. Made from 60-micron, 100% recycled LDPE, they’re moisture-proof (water-resistant), opaque for privacy, and close fast with a tamper-evident self-seal strip.

Not the size you need? See all sizes.

Why this 14×21" size?

When 13×19" starts to feel tight, 14×21" adds length and a little width for outerwear, textile sets, and retail boxes that don’t need a rigid carton. If you’re packing bulkier bedding, step up to 17×24". For coats or multi-item bundles, consider 15×18" (wider) or 17×24" (bigger overall).

Real use examples (what typically fits)

  • Apparel: jackets, thick knitwear, sweat sets, stacked tees.
  • Textiles: throws, cushion covers, towel sets in sleeves.
  • Boxed goods: larger books/catalogues, retail kits with padded corners.

Fit & packing guidance

  • Best fit: outerwear, textile sets, larger A4 packs, bulkier apparel.
  • If it strains at the seal: move up to 17×24".
  • If it’s roomy: step down to 13×19" to cut void space and postage.
  • Corner care: pad or round inner-box edges to reduce punctures.
  • Press out air: flatten before sealing so labels stick flat and sacks stack neatly.

Key benefits

  • Self-seal, tamper-evident closure for fast, secure 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, professional look.
  • Recyclable LDPE — remove the glue strip before recycling.

Specifications

Spec Value
Size (inches) 14 × 21"
Size (mm) 356 × 533 mm
Thickness 60 µm
Material LDPE (Low-Density Polyethylene), 100% 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

Film: 60 µm, 100% recycled LDPE (code 4). Recyclable in many UK schemes — please remove the adhesive strip first. Not biodegradable or compostable.

Strength & Protection

Co-extruded film for puncture and tear resistance. The self-seal adhesive forms a permanent bond once pressed. The opaque grey finish hides contents and looks tidy on arrival.

Storage & Performance

Store at 13–21 °C out of direct heat/sunlight. Let cold stock acclimatise before use for best adhesive performance.

Lightweight = Lower Postage

LDPE mailers are exceptionally lightweight versus cartons, helping you stay in lower weight bands when the product doesn’t need a rigid box.

Size comparison (choose the right bag)

Size Inches Millimetres Typical fit
Step down 13 × 19" 330 × 483 mm Bulkier apparel, larger books
This page 14 × 21" 356 × 533 mm Jackets, textile sets, larger A4 bundles
Step up 17 × 24" 432 × 610 mm Bedding sets, bulkier textiles, larger boxed goods

Packing tips

  • Use a light inner sleeve for dusty items or sharp corners.
  • Fold textiles flat; avoid hard creases that form sharp edges.
  • Apply labels on a smooth, clean area; press firmly for reliable scanning.
  • Add invoices/returns in a clear document wallet on the outside.

FAQs

Is 14×21" big enough for a jacket?

Yes, it suits most jackets and thicker knits. If the seal feels tight, step up to 17×24".

Are these bags waterproof?

They’re moisture-proof / water-resistant. For very wet routes, add an inner sleeve.

Are they recyclable?

Yes — LDPE (code 4). Please remove the glue strip before recycling.

Need a different fit? See all sizes or browse the full Mailing Bags range.

Build a complete packing setup

Team your grey mailing bags 14×21" with packaging tape, document wallets, and cardboard boxes.

Features
FAQs
Shipping

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

Reviews

Customer Reviews

Based on 64 reviews
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(64)
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H
Holly Edwards
No Issues

No issues at all – just good products from a good company

R
Rosie Morgan
Stronger Than Expected

These bags feel way stronger than they look

A
Alexander Kelly
Trusted Company

Trustworthy company with great packaging materials

M
Mia Lewis
Reordered Again

I’ve reordered a few times because these bags are just that good

J
Jessica Price
Reliable Quality

Reliable and clean – can’t fault either the bags or the service