Custom End-Opening Mailer Boxes

Board Grades for End-Opening Mailer Boxes

End-opening mailers are usually made from corrugated board, which gives the strength to survive sorting machines and stacked delivery vans. A thin E-flute gives a smooth printing surface and a slim profile, which suits cosmetics, books and small electronics. A thicker B-flute or a double-wall board protects heavier or more fragile items, such as glass bottles or small homeware.

The outer liner can be white or brown kraft. White gives bright colour print and a polished look. We can print the outside, the inside or both, depending on the impression you want to make.

For very light, flat items such as prints or cards, a rigid folding board version without corrugation can be enough, keeping weight and cost down.

Printing for the Doorstep and the Unboxing

A mailer is seen twice: once on the doorstep and again when it is opened. The outside should carry your logo clearly and make the parcel recognisable, but many brands keep it quite simple for security, avoiding anything that shouts about valuable contents. The real reveal happens inside.

Printing the inside of an end-opener is particularly effective, because the customer sees the printed interior as the contents slide out. A pattern, a thank-you message or a short note about the product makes the moment feel considered without needing extra inserts.

If your products vary, a branded mailer in a few standard sizes keeps packing simple. Product-specific information can go on a printed insert or sticker rather than a different box for every item.

Speeding Up Packing in a Small Warehouse

For a busy online shop, the real cost of a mailer is not just the box price but the minutes spent packing it. End-openers are quick because the product slides in from one end and the box seals with a single strip, rather than folding a lid, adding void fill and taping several edges. Over a day of orders, those saved seconds add up to hours.

Keep a few habits in mind to make the most of it. Fold a batch of boxes before orders come in, leaving only the sealing end open. Store them on their side so staff can grab one and slide a product straight in. If you use a printed insert or thank-you card, keep it the same width as the box so it slides in alongside the product without catching.

Returns are part of packing too. A double-seal end-opener lets customers reuse the same box, which cuts down on lost returns and the cost of sending replacement packaging.

Measuring for a Snug Fit

Measure the product or its retail box at the longest, widest and deepest points. Add a small allowance for board thickness and an easy slide, but not so much that the item moves around. If you send products in their own retail cartons, measure the carton rather than the product.

Think about postage sizes too. Many couriers and postal services price by size bands, and a few millimetres can move a parcel into a more expensive band. If you tell us your target postage size, we will aim to keep the outside dimensions within it.

If you have several products, list them and their sizes. Two or three mailer sizes often cover a whole range, which keeps ordering and storage straightforward.

A quick test with an old box cut to size can save surprises: if the product slides in with a finger's push and does not fall out when the box is tipped, the fit is right.

Turnaround and Delivery

Once we have your sizes and quantities, we will email a custom quote within one working day. Minimums stay low and depend on the job, with plain end-openers starting from £0.25 each.

A free design proof shows your mailer flat, with closures and print areas marked. After approval, production takes 4–7 working days, and boxes arrive flat on free tracked delivery to UK mainland addresses within 2–3 working days. Damaged or misprinted mailers reported within 10 days are put right with a reprint or a refund.