The right mailing bag fits your item without stretching, closes cleanly and leaves a flat surface for the address label. Start with the contents and their packed size, then choose your colour and pack quantity. For clothes and other soft goods, self seal postage bags offer a straightforward way to prepare an order for dispatch.

At iSOUL, you can explore blue, baby pink, grey, hot pink, red and purple mailing bags. This guide explains how to compare them, when to choose large postage bags and which packing details to check before you send a parcel.

What are mailing bags and postage bags?

In everyday online selling, mailing bags, postage bags, parcel bags and shipping bags often describe flexible outer packaging for items sent by post or courier. A plastic mailer usually has an opening at one end and a flap that closes over it. Self seal versions use an adhesive strip to hold that flap in place.

These names do not tell you everything about the product. Postal bags can differ in material, thickness, dimensions and closure, while some mailers include padding and others do not. Check the selected product rather than assuming that every bag described as a mailer offers the same protection.

Flexible plastic postage bags are worth considering for suitable clothing and textiles. Items that can break, bend or puncture the outer packaging may need a box, protective wrap or a more specialised solution.

How to choose the right mailing bag size

Measure the item as you intend to pack it. A folded T-shirt and a thick jumper can have a similar width but need very different amounts of room. Include any inner packaging in your measurements, and leave enough space for the flap to close without pulling on the contents.

A bag's advertised width and length describe a flat format, not a guaranteed internal capacity. Thickness takes up some of that space. Check whether the stated length includes the flap, and try a small pack before committing to a large order if the fit is close.

The following examples appear in iSOUL's collection size guides. They are starting points for comparison, not guaranteed fits for every garment.

For intermediate larger formats in red and purple, check the selected product carefully. Always confirm the dimensions, availability and quantity for the product you select. Switching colour does not necessarily mean you will get the same largest size.

When should you use large postage bags?

Large mailing bags can be useful for clothing bundles, bulky knitwear or other soft items that are awkward to fit in smaller packaging. Choose the smallest suitable format that allows a comfortable fit and a secure closure.

More room is not always better. An oversized bag can leave loose material around the parcel, while an undersized one can put strain on the seams and closing flap. If an item is heavy, sharp or fragile, moving to a larger plastic bag alone does not solve the protection problem.

For larger formats, compare the grey mailing bags with your preferred colour collection. Measure the sealed parcel afterwards, because the carrier assesses the finished package, including its thickness and weight.

Choose from six mailing bag colours

Colour is a presentation choice. It can match your shop's branding or help your team distinguish packing supplies, but it does not replace the need to choose the correct size and protection.Blue mailing bags offer a calm colour option for a consistent dispatch style across clothing and soft accessories.

• Baby pink mailing bags create a lighter colour theme that pairs neatly with simple white address labels.
• Grey mailing bags provide a neutral finish and the broadest listed size range among these six collections.
• Hot pink mailing bags are the brighter pink option for shops using a vivid colour palette.
• Red mailing bags can match red branding or form part of a seasonal parcel presentation.
• Purple mailing bags offer another distinctive colour choice. Check dimensions when switching from other colours.

Baby pink or hot pink postage bags?

Choose baby pink for a softer shade or hot pink for a more vivid finish. If you already use pink in your branding, compare a physical sample with your printed materials: screens, lighting and photographs can make colours look different. Keep the parcel label readable whichever shade you choose.

How to pack clothes in self seal postage bags

1. Prepare the garment. Make sure it is clean and dry, fold it neatly and protect any detail that could catch or pierce the outer bag.
2. Check the fit. Slide the item into the bag without forcing it. Include any inner wrapping you need and keep fabric away from the closing flap.
3. Close the bag. Follow the product's sealing instructions. With a peel-and-seal strip, remove the release liner, fold the flap onto a clean surface and press along the full adhesive area.
4. Apply the address label. Use a smooth area of the parcel. Keep the address and barcode clear, without wrapping the barcode around an edge or over a fold.
5. Measure and weigh the finished parcel. Select the service that matches the sealed package and the carrier's packaging requirements.

For suitable soft items, the bag can serve as the outer packaging. It does not provide the rigid protection that a box offers. Use extra protection when the contents need it, and check your marketplace or carrier's packing instructions before dispatch.

Single-size packs or mixed-size packs?

A single-size pack makes sense when you repeatedly send the same type of item. Mixed-size packs can help if you sell a changing selection of clothes or are still learning which formats you use most.

Compare both the total pack price and the cost per usable bag. For example, a hypothetical £10 pack containing 100 bags costs 10p per bag. That is only good value for your operation if those bags fit the products you actually send. This example is a calculation, not an iSOUL price offer.

Check the number of bags in each size within a mixed pack. The colour collections contain different product options, so confirm the selected pack's contents rather than relying on the headline quantity alone.