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Shoebox Packed In A Large Grey Mailing Bag 16" x 21" Large Grey Mailing Bags (A2 Size) – Heavy Duty Shipping for Large Items & Bundles £3.50 – £40.50Price range: £3.50 through £40.50
12" x 16" Medium Grey Mailing Bags (A3 Size - 300mm x 400mm) – Ideal for Jumpers, Jeans & Shoe Boxes (Pack of 25) 12" x 16" Medium Grey Mailing Bags (A3 Size - 300mm x 400mm) – Ideal for Jumpers, Jeans & Shoe Boxes (Pack of 25) £3.00

16″ x 21″ Large Grey Mailing Bags (A2 Size) – Heavy Duty Shipping for Large Items & Bundles (pack of 25)

£3.50

What Fits in This Bag?

  • Winter Wear: Puffer jackets, heavy overcoats, and chunky wool knitwear.

  • Footwear: Large adult shoeboxes or multiple pairs of trainers.

  • Home Goods: Single duvets, throw pillows, or complete bedding sets.

  • The “Mega Bundle”: The perfect solution for Vinted or eBay sellers shipping 5-10 items of clothing in a single transaction.

10 in stock (can be backordered)

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16" x 21" Large Grey Mailing Bags (A2 Size) – Heavy Duty Shipping for Large Items & Bundles (pack of 25)
16" x 21" Large Grey Mailing Bags (A2 Size) – Heavy Duty Shipping for Large Items & Bundles (pack of 25)
£3.50
This item is selling fast!

Why Thousands of UK Sellers Choose Packaging365

  • Royal Mail & Evri Ready: All our bags and boxes are tested against UK courier dimensions to help you avoid unexpected surcharges.

  • Dispatched in 24 Hours: We know your customers are waiting. Orders placed before 2 PM are processed the same day for lightning-fast UK delivery.

  • Eco-Conscious Packaging: We prioritise 100% recyclable materials, helping your small business stay green without the high price tag.

  • No-Hassle Returns: Not the right size? No problem. We offer a 30-day money-back guarantee for all unused packaging

  • Free shipping on all orders over £50
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Stop struggling with small bags that split at the seams. Our 16″ x 21″ Large Grey Mailing Bags are the “Large Parcel” heroes of our range. Specifically designed for the “bulky” side of reselling, these bags are essential for shipping heavy winter wear, boxed footwear, or large multi-item bundles.

Engineered from premium, co-extruded polythene, these bags offer superior puncture resistance, ensuring that even sharp box corners won’t break through during the rough-and-tumble of UK courier sorting centers.

Why Sellers Love the 16×21 Size:

  • Built for Bulk: The generous capacity easily accommodates larger items that standard mailers can’t touch.
  • Heavy-Duty Security: Featuring a high-tack, permanent “peel and seal” strip. Once shut, it stays shut until your customer cuts it open.
  • 100% Opaque & Discreet: Opaque grey mailing bags offer total privacy for high-value contents, from designer boots to electronics.
  • Weather-Proof Protection: Rain stays out and your products stay dry, providing professional peace of mind for every shipment.
  • Tear-Resistant Technology: Flexible yet incredibly strong, these bags are built to handle the weight of heavy textiles without failing.

What Fits in This Bag?

  • Winter Wear: Puffer jackets, heavy overcoats, and chunky wool knitwear.
  • Footwear: Large adult shoeboxes or multiple pairs of trainers.
  • Home Goods: Single duvets, throw pillows, or complete bedding sets.
  • The “Mega Bundle”: The perfect solution for Vinted or eBay sellers shipping several items of clothing in a single transaction.

Additional information

Weight0.45 kg
Pack Size (Bags)

25

Colour

Grey

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Mailing Bags Size Guide

Packing a t-shirt in a grey mailing bag

Not sure which bag you need for your Vinted or eBay sales? Use our mailing bags size guide below to find the perfect fit for your items. All our bags are lightweight to help you stay within Royal Mail and Evri weight limits.

Quick Reference Chart

Bag Size (Inches)Metric Size (mm)Best For…Royal Mail Format
9 x 12″225 x 300 mmT-Shirts, Leggings, Thin Summer Dresses, A4 DocumentsLarge Letter (if < 25 mm thick)
12 x 16″300 x 400 mmThe “Workhorse”: Hoodies, Jeans, Coats, Small Shoe Boxes, Small BundlesSmall Parcel
16 x 21″400 x 525 mmWinter Coats, Boots, Larger Shoe Boxes, Multi-item “Bundles”Small/Medium Parcel

🧥 Which bag for my item?

  • T-Shirts & Tops: Most single t-shirts fit perfectly in a 9×12″ bag. If the fabric is very thin, you can often keep this under 2.5cm thick to post as a Large Letter, saving you nearly £2.00 in postage!
  • Jeans & Trousers: Adult jeans are bulky. We recommend the 12×16″ bag. It allows room for the denim to be folded without putting stress on the seams.
  • Hoodies & Knitwear: For a standard adult hoodie, go for the 12×16″. If it’s an extra-thick “oversized” hoodie or a winter coat, move up to the 16×21″.
  • Vinted Bundles: If a buyer has bought 3–5 items, the 16×21″ is your best friend. It’s heavy-duty and large enough to keep everything together in one secure package.

📏 Top Packing Tips for Sellers

  1. The “Air Squeeze”: Before sealing the bag, press down to remove excess air. This makes the parcel flatter and less likely to get caught in courier machinery.
  2. The Fold Test: If your item is right on the edge of two sizes, go for the larger one. You can always fold the excess plastic over and tape it down, but you can’t stretch a bag that’s too small!
  3. Check the Depth: Remember, Royal Mail “Large Letter” is about the thickness (25mm), not just the width. If your t-shirt is folded too “fat,” it will be charged as a Small Parcel.
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