Mailer Box Styles: Which Closure Suits What You Post
Every mailer box in this range is one piece of corrugated board that folds up without glue, and the only real difference between them is how the lid shuts and which side opens. Pick the closure to match the product, the packing speed you need and whether the customer will open it on camera.
- From £0.25 a box on a written quote
- Free design proof first
- 4 to 6 working days to make
- Free tracked UK mainland delivery
6 box styles to choose from
Every one is cut to your inside size and quoted in writing before you commit to anything.
Tuck Top Mailer BoxesRoll-over front, tuck-in lid, prints inside and outFrom £0.25 a box
Ear Lock Mailer BoxesTape-free close for unboxing on cameraFrom £0.25 a box
Side Loading Tab Lock MailersSlide in from the side, lock with two tabsFrom £0.25 a box
End Open Mailer BoxesShort-end opening for books, frames and setsFrom £0.25 a box
Double Sided Printed Mailer BoxesPattern or message inside, brand on the outsideFrom £0.25 a box
Folding Small Mailing BoxesFlat-packed, folds up in seconds, from 100 mmFrom £0.25 a boxDesign Your Mailer Box Styles Mailer Box
Pick any of the 6 box styles, upload your logo and place it on the box. A free proof follows before anything is printed.
Your logo is placed on a real photo of our box. A designer redraws it to scale on the dieline and sends a free proof before anything is printed.
Six ways a mailer box can close
A mailer box is cut flat, scored and folded up by hand as you pack. What changes between the six styles here is the closure: how the lid holds shut and where the box opens.
That single detail decides how the box feels to open, how fast a packer can fold it and how well it carries the item inside. Between them, the six styles cover almost every job a UK seller posts, from a lipstick to a framed print.
Each one is made to your inside size on brown kraft or white-lined board, plain or printed. Try your logo on a box on the Design Your Mailer Box page and a proof comes back before anything is printed.
Which mailer box style is right for your product?
Work through these questions in order and the style usually picks itself.
- Measure the item and add 3 to 5 mm a side. That figure is the inside size you will ask for.
- Decide whether the box should open from the top, the long side or the short end. Flat goods such as prints and brochures load more easily from a side.
- Ask whether the customer will film the opening. If so, choose a closure that needs no tape, such as an ear lock.
- Check the depth. Anything under about 20 mm inside may land in Royal Mail Large Letter, which favours a shallow side loading style.
- Count how many parcels you pack an hour. A tuck top or folding small box folds up fastest and needs no training.
- Decide what the inside should say. A double sided printed box carries a message or pattern under the lid.
If two styles still fit, name both on the quote and we will tell you which costs less at your size.
Tuck top or ear lock: what is the difference?
The tuck top mailer box is the standard ecommerce mailer. The front panel rolls over, the lid comes down and a long tongue tucks behind the front wall, while two dust flaps close off the sides.
An ear lock box has the same lid but adds a locking ear on each side flap. The ears push into slots in the front wall and hold the lid down on their own, so the parcel travels without a strip of tape across it.
Choose tuck top for plain packing and repeat orders where tape is already on the bench. Choose ear lock when the box is opened in front of a phone, because it shuts with a click and opens clean.
Side loading, end open and folding small: the flat and small jobs
Three styles in the range are built around a shape rather than a lid. Side loading tab lock mailers open along the long edge; the contents slide in and two tabs lock the flap down. They suit prints, documents and folded clothing that must stay flat.
End open mailer boxes open at the short end instead. A book, a frame or a boxed set slides in lengthways with its edges supported, and the end flap tucks shut.
Folding small mailing boxes are the smallest of the six, from around 100 mm long. They arrive flat, fold up in a few seconds and are the usual pick for jewellery, cosmetic samples and phone cases.
- Side loading tab lock: long-edge opening, two locking tabs, flat goods
- End open: short-end opening, slide-in loading, books and sets
- Folding small: smallest sizes, quickest fold, tiny items
All three can be printed, though many sellers keep the small and end open boxes plain and let a sticker carry the brand.
How do the six mailer box styles compare?
The table sets the six styles side by side. The sizes shown are typical starting inside sizes, and every box is cut to the size you ask for.
| Style | Opens from | Holds shut by | Typical inside size | Suits |
|---|---|---|---|---|
| Tuck top | Top | Tongue tucked behind the front | 250 x 180 x 80 mm | Most ecommerce orders |
| Ear lock | Top | Two side ears in front slots | 250 x 180 x 80 mm | Unboxing, gifts, kits |
| Side loading tab lock | Long side | Two locking tabs | 300 x 220 x 50 mm | Prints, documents, flat clothing |
| End open | Short end | Tucked end flap | 300 x 220 x 60 mm | Books, frames, boxed sets |
| Double sided printed | Top | Tongue or ears | 250 x 180 x 80 mm | Print inside and out |
| Folding small | Top | Tongue tucked behind the front | 160 x 110 x 50 mm | Jewellery, samples, small parts |
Double sided printed is a print option as much as a style. It is usually a tuck top or ear lock box with artwork on both faces of the board, and the double sided printed mailer boxes page shows how the inside artwork sits under the lid.
Does the style change the board or the print?
Not much. All six styles are cut from the same two corrugated boards. E-flute at 1.5 mm gives a smooth face for fine print and folds crisply on small boxes, while B-flute at 3 mm is the thicker choice for larger boxes and anything that needs more wall.
Print is the same across the range too: plain, one colour, two colours or full colour, outside, inside or both, with a white underprint if you want bright colour on kraft. Matt or gloss varnish can go over the top.
The one thing to watch is how a lock behaves on thin board. Ear locks and tab locks hold better on B-flute once a box passes about 300 mm on its longest side, and the guide to E-flute and B-flute walks through the trade-offs.
How to order a mailer box style
Send the inside size, the style, the board and what you want printed. Minimums are low and quoted per job, and prices start from £0.25 a box on the written quote, which comes back within one working day.
A free design proof follows. Once you approve it, production takes 4 to 6 working days and free tracked UK mainland delivery adds 2 to 3 working days.
Not sure which style? Describe the product and how it will be opened on the mailer box quote form and we will suggest one.
Mailer Box Styles questions
Which mailer box style can be posted as a Large Letter?
A shallow side loading tab lock mailer with an inside depth of about 20 mm can land in Royal Mail Large Letter, because the outside size counts. Band limits change, so confirm them before you order.
Can a tuck top mailer box be sent without tape?
It can, but the tongue may work loose in a sorting bag. For a tape-free parcel an ear lock mailer box is the safer pick.
Do ear lock mailer boxes cost more than tuck top boxes?
Usually a little, because the dieline has more cuts and uses slightly more board. Both are quoted per job, so ask for both on one quote and compare.
What goes in a side loading tab lock mailer?
Prints, photographs, calendars, documents, folded shirts and anything else that should arrive flat. The long-side opening means nothing has to bend to get in.
Why choose an end open mailer box over a tuck top?
A book or framed item slides in lengthways with all four edges held by the walls. A tuck top needs the item dropped in from above, which is awkward for tall flat goods.
How small can folding small mailing boxes go?
Down to about 100 x 80 x 30 mm inside. Below that the flaps become too short to hold, and a padded mailer does the job better.
Is a double sided printed mailer box a different shape?
No. It is a tuck top or ear lock box printed on both faces of the board, so the inside of the lid and base carry artwork as well as the outside.
Which mailer box styles can be printed inside?
All six. Inside print is most used on tuck top, ear lock and double sided printed boxes, where the lid opens wide and the message is seen first.
Can I mix two mailer box styles on one order?
Yes. Each style is its own dieline, so they are quoted as separate lines, but they are proofed, printed and delivered together.
Do all the mailer box styles arrive flat?
Yes. Every box in the range ships flat in bundles and is folded up by hand as you pack. There is no glue to set and no corner to tape.
Your question is not here? Ask on WhatsApp or call +44 7578 382054.
Tell us what you post
Send the product, a rough inside size and a quantity. We reply in writing within one working day with a price and a free design proof. Prefer to talk? Call +44 7578 382054 or message us on WhatsApp.