Parcel Bags and Postal Bags: Sizes, Colours and Large Mailing Bags

Parcel bags are opaque polythene bags with a self-seal strip. You slide the item in, peel the backing, press the strip down and the parcel is ready to post. Online sellers use them for clothing, soft goods, books and documents because the bag adds very little weight to the parcel.

Pack Solution stocks grey parcel bags in 16 sizes, from 4 x 6" (100 x 150mm) up to 34 x 42" (850 x 1050mm), plus white, green, purple, baby blue and hot pink in five sizes each. Black is the one colour we do not stock, so there is a short section on what to use instead.

Quick Picks: Parcel Bags for Three Common Jobs

For the widest choice of size, pick grey mailing bags. For a clean finish that takes any logo, label or handwritten address, pick white mailing bags. For a bright parcel that stands out on the doormat, pick green mailing bags.

Best for the widest choice of size

Grey Mailing Bags

Opaque grey polythene with a self-seal strip and 16 sizes, from small accessories up to bedding and other bulky soft items.

• 16 sizes, 4 x 6" (100 x 150mm) to 34 x 42" (850 x 1050mm)
• Packs of 100, 50 or 25 depending on size
• Water resistant outer

From £2.90 ex VAT (£3.48 inc VAT)

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Best for a clean look with any logo or label

White Mailing Bags

Opaque white polythene with a self-seal strip and 50mm lip. A white surface shows a label or handwritten address clearly.

• 5 sizes, 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm)
• Pack of 100 per size
• Tamper evident seal

From £4.50 ex VAT (£5.40 inc VAT)

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Best for a parcel that stands out

Green Mailing Bags

Bright green opaque polythene with a self-seal strip and 50mm lip, in five sizes that match the white range.

• 5 sizes, 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm)
• Pack of 100 per size
• Opaque, lightweight and water resistant

From £4.50 ex VAT (£5.40 inc VAT)

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Key Facts About Parcel Bags

• Grey mailing bags come in 16 sizes, from 4 x 6" (100 x 150mm) to 34 x 42" (850 x 1050mm).
• White, green, purple, baby blue and hot pink mailing bags come in five sizes each, from 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm), in packs of 100.
• Grey packs hold 100 bags up to 17 x 24", 50 bags from 20 x 26" to 28 x 34", and 25 bags at 34 x 42".
• Every bag is opaque polythene with a self-seal adhesive strip and a water resistant outer.
• Sizes are width x length. A 9 x 12" (230 x 300mm) bag takes an A4 sheet (210 x 297mm) flat.
• Orders placed by 2pm Monday to Friday are dispatched the same working day from Manchester.

What Are Parcel Bags and Postal Bags?

Parcel bags and postal bags are two names for the same product: a lightweight polythene bag that you fill, seal with its own adhesive strip and post. No tape is needed.

You will also see them sold as mailing bags and courier bags. In the trade they are poly mailers or polythene mailing bags. Poly bag mailers and poly mailing bags are two more labels for the same bag. Some sellers also say poly bags for mailing. A shipping bag of this kind is opaque, so nobody can see what is inside the parcel.

The outer is water resistant, which protects the contents from rain in transit. The bags suit soft, non-fragile goods, which is why sellers on eBay, Etsy and Vinted use them for clothing, textiles, books and documents. Poly shipping bags are the same product again, and clothing sellers can find size help in our guide to mailing bags for clothes.

Parcel Bag Sizes From Small to Extra Large

Grey parcel bags run through 16 sizes, from 4 x 6" (100 x 150mm) to 34 x 42" (850 x 1050mm). Sizes are width x length, and the number of bags in a pack falls as the bag gets bigger.

Small Courier Bag Sizes

The two smallest grey sizes, 4 x 6" (100 x 150mm) and 6 x 9" (165 x 230mm), work as a small courier bag for accessories and A5 items. Both come in packs of 100.

Large Mailing Bags and Large Parcel Bags

From 17 x 24" (425 x 600mm) the range moves into large mailing bags for bulky soft goods such as bedding and cushions. From 20 x 26" (508 x 660mm) up, the bags also work as extra large mailing bags and large parcel bags. If you need large postage bags for one bulky item, or a single large parcel bag for a duvet, measure the item first and compare it with the width and length in the table.

Parcel Bag Colours: Grey, White, Green, Purple, Baby Blue and Hot Pink

Pack Solution sells these bags in six colours: grey in 16 sizes, and white, green, purple, baby blue and hot pink in five sizes each. All six are opaque polythene with a self-seal strip.

The five colours beyond grey share one specification: a self-seal strip with a 50mm lip, an opaque film, a tamper evident seal that is difficult to open once closed, and a lightweight, water resistant finish.

Purple and Baby Blue

Purple mailing bags suit boutique and gift brands. Their sizes in centimetres are 23 x 30cm, 25 x 35cm, 30.5 x 40.5cm, 35.5 x 51cm and 43 x 56cm. They are mailing bags for posting parcels, so they are not bin bags or council collection sacks.

Best for boutique and gift brands

Purple Mailing Bags

Opaque purple polythene with a self-seal strip, in five sizes. A different parcel colour from plain grey.

• 5 sizes, 23 x 30cm up to 43 x 56cm
• Pack of 100 per size
• Tamper evident, 50mm lip

From £4.50 ex VAT (£5.40 inc VAT)

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Baby blue mailing bags cover the same five sizes. If you are unsure which to pick, order a single pack of two sizes and test them with your own stock.

Best for a bright branded parcel

Baby Blue Mailing Bags

Opaque baby blue polythene with a self-seal strip and 50mm lip, in five sizes from A4-friendly to large.

• 5 sizes, 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm)
• Pack of 100 per size
• Opaque and tamper evident

From £4.50 ex VAT (£5.40 inc VAT)

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Hot Pink

Hot pink mailing bags are a bright, strong pink rather than a pale or pastel shade. The opaque film keeps the contents private, which matters for lingerie and gifts.

Best for lingerie, beauty and gift orders

Hot Pink Mailing Bags

A vivid hot pink in opaque polythene that keeps contents private, with a self-seal strip and 50mm lip.

• 5 sizes, 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm)
• Pack of 100 per size
• Opaque film, tamper evident

From £4.50 ex VAT (£5.40 inc VAT)

Choose sizeView product

Black Courier Bags: What to Use Instead

Pack Solution does not sell black courier bags or any black mailing bags. The closest option is grey, which is opaque, so nobody can see what is inside the parcel.

If your brand needs a courier bag black in colour, we do not stock one, so grey or white are the plain, neutral choices on our shelves. Grey suits a darker, understated look, and white suits a clean one that takes a logo or sticker. Both are self-seal and water resistant. There is more on the grey range in our grey mailing bags article.

Plastic Mailing Bags or Boxes?

Plastic mailing bags suit soft, non-fragile items such as clothing, textiles, books and documents. Anything rigid, breakable or easily crushed belongs in a box, because a bag adds no crush protection.

Plastic bag mailers add very little weight, which helps keep postage costs down. Plastic postage bags and plastic postal bags are the same product under other names, so a listing with either label points to the same kind of polythene bag with a sticky strip.

• Bag: folded clothing, bedding, cushions and other soft goods.
• Bag: A4 paperwork, catalogues and printed matter laid flat.
• Box: fragile, rigid or crush-prone items.
• Padded envelope: small items that need a cushion, as covered in the padded envelope sizes guide.
• Board-back envelope: flat items that must not bend, as covered in the postal envelopes guide.

How to Choose and Seal Parcel Bags

Measure the item as it will travel, pick the next size up, then peel the backing and press the strip down. Once the size is right, sealing is one motion.

1. Fold or flatten the item the way it will be posted.
2. Measure the width and the length, and allow a little room for thickness so the seal lies flat.
3. Pick the bag whose width x length is just above your measurements.
4. Slide the item in without forcing it, and keep the sealing strip clear of the contents.
5. Peel the backing off the adhesive strip. On the coloured bags, fold the 50mm lip over first, then press along the whole strip.
6. Add the address on a printed label, or write it by hand on a white bag.

Buying Parcel Bags in Bulk

Parcel bags are priced per pack, ex VAT, and the price per pack falls automatically as you add more packs to the basket. Volume pricing is shown on each product page.

Orders placed by 2pm Monday to Friday are dispatched the same working day from Manchester. Royal Mail Tracked 48 is free on every order with no minimum, and Express and DPD options are available when a parcel is needed sooner. Details are on the shipping policy page. Unused items can be returned within 30 days of delivery under the refund policy, so a new size can be tried and sent back if it does not suit.

Parcel Bag Checklist Before You Order

• Measure the item folded, in width x length.
• Choose the next bag size up so the strip lies flat.
• Check the pack size: 100 for most sizes, 50 for 20 x 26" to 28 x 34", 25 for 34 x 42".
• Pick a colour: grey for discretion, white for a clean look, or a bright shade for a branded parcel.
• Move fragile or rigid items to a box.
• Order before 2pm on a weekday for same-day dispatch.

Choosing Your Parcel Bags

Start with the item: measure it folded, match it to a width x length and pick a colour. Grey covers the full range from 4 x 6" to 34 x 42", and the five brighter colours stop at 17 x 22". The full range is in our bags collection, with the pack quantity shown for every size.

Frequently Asked Questions

What are the largest parcel bags you sell?

The largest are Grey Mailing Bags in 34 x 42" (850 x 1050mm), sold in packs of 25. The 20 x 26", 21 x 24", 22 x 30", 24 x 36" and 28 x 34" sizes come in packs of 50. These work as large mailing bags for bulky soft goods such as bedding and cushions.

Do you sell black courier bags?

No. We do not stock black courier bags or any black mailing bags. The nearest alternative is Grey Mailing Bags, which are opaque grey polythene with a self-seal strip. White Mailing Bags are another neutral choice, available in five sizes from 9 x 12" to 17 x 22".

Which postal bags fit an A4 sheet?

The 9 x 12" (230 x 300mm) size takes an A4 sheet (210 x 297mm) flat. It is available in grey, white, green, purple, baby blue and hot pink, in packs of 100. For extra room, choose 10 x 14" (250 x 350mm).

What colours do mailing bags come in?

We sell opaque mailing bags in grey, white, green, purple, baby blue and hot pink. Grey comes in 16 sizes. The other five colours each come in five sizes, from 9 x 12" (230 x 300mm) to 17 x 22" (430 x 560mm), in packs of 100.

Are plastic mailing bags waterproof?

The bags have a water resistant outer that protects contents from rain in transit, but they are not described as waterproof. Press the self-seal strip down along its full length before posting. Rigid or fragile items should go in a box rather than a plastic mailing bag.

What is the smallest courier bag you sell?

The smallest is the grey 4 x 6" (100 x 150mm) bag, a small courier bag for accessories, sold in packs of 100. The next size up, 6 x 9" (165 x 230mm), takes an A5 item (148 x 210mm) flat and also comes in packs of 100.

Shop for This Job

• Mailing & Polythene Bags

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