Custom Foldable Mailer Boxes
Custom foldable mailer boxes that arrive flat and fold without tape in seconds — self-locking lid, inside print, E flute, sized to your product — from 100. Dieline and price the same working day.
Flat until the moment it is needed, then a box in ten seconds
- Board
- E flute kraft or white-lined; B flute for weight or distance
- Builds
- One-blank self-locking mailer; double side walls; tuck lid
- Assembly
- Under ten seconds; no tape; re-foldable
Get a price for Foldable Mailer Boxes
Send the size and quantity — we reply the same working day with a price, a dieline and a date. Artwork optional at this stage.
- Free dielineThe flat drawing comes with the quote, before you commit.
- Proof before pressNothing is printed until you have seen it laid on the dieline.
- Die kept for reordersTooling is paid once. Every reorder skips straight to press.
- Quoted in four marketsUS, UK, Canada and Australia, in the delivery currency.
Six folds and two tucks from one blank
Six folds and two tucks. A packer does it in under ten seconds without looking after the first few.
| Base | The center panel; the walls fold up from it |
|---|---|
| Side walls | Double-thickness; the outer fold locks into slots in the base |
| Front wall | Folds up and carries the lid tuck slots |
| Lid | Hinged at the back; front tuck locks into the front wall |
Why it wins on a bench
Our assorted mailer boxes in a size run plan the same box across the sizes an order profile needs.
- No tape — the lid locks and the box opens cleanly at the other end.
- Flat storage — a hundred boxes in the space of ten.
- Prints inside and out on the same pass, so the unboxing is designed.
- Reusable for a return — it folds flat again and locks again.
Board and the journey
E flute with a kraft or white liner for most; B flute for a box over about 2 kg or a long journey. The double side walls and the locked lid give a mailer more crush strength than a taped carton of the same board. Sized to the product plus 5–10 mm, so nothing moves and no void fill is needed.
A mailer that ships alone through the post is built one flute grade heavier than one that goes in a courier bag.
Print for the doorstep and the table
Outside, the brand in one or two colors on kraft or full color on white. Inside, the lid liner and the base, seen when the box opens — a pattern, a message, a color. A tear strip on the lid makes the first open clean; a second lock strip lets the box be resealed for a return.
Runs and the die
One die per size, kept. A hundred boxes is a launch; a few thousand is a quarter. Reorders run from the kept die and file, and a new print on the same size is a print change.
Foldable Mailer Boxes — specification
The rows that are specific to this build first, then what applies to every job we run. Anything not listed is a question, not a limit — send the brief.
This build
- Board
- E flute kraft or white-lined; B flute for weight or distance
- Builds
- One-blank self-locking mailer; double side walls; tuck lid
- Assembly
- Under ten seconds; no tape; re-foldable
- Sizing
- Product plus 5–10 mm; no void fill
- Outside and inside on one pass; tear strip; return lock strip
- Supply
- Flat blanks, bundled
- Minimum
- 100 boxes
On every job
- Print process
- Flexo in one to four colors straight onto the liner; litho-lamination where the box needs full color or a photograph.
- Color
- Flat colors on kraft. Full color needs a white top liner or a laminated sheet, because brown shifts every color warm.
- Tolerance
- Cutting plus or minus 1.5 mm. The flute compresses, so corrugated runs wider than folding board.
- Tooling
- No die on a regular slotted box, which is cut on a slotter. Die-cut mailers and trays need one, made once and kept.
- Food contact
- Food-grade liners and a vented build where the box carries hot food.
- Sustainability
- High recycled content through liners and flute as standard, and the box recycles whole if it is sealed with paper tape.
- Artwork
- Vector PDF or AI, 3 mm bleed, 4 mm safe area, fonts outlined. We check every file and send a proof before press.
- Dieline
- Supplied free with the quote, before you commit. Yours whether or not you order.
- Sample
- A plain unprinted sample at the finished size on request, for fit and construction.
- Reorders
- Skip the tooling and go straight to press at a lower unit price.
- Lead time
- Quoted with the price against your fill date rather than promised before we have seen the spec.
- Markets
- United States, United Kingdom, Canada, Australia — priced in the delivery currency, freight included.
Boards and films we build foldable mailer boxes on
Corrugated is a fluted sheet glued between two liners, and the flute decides nearly everything: how it prints, how it dents, how high it stacks. These are the grades we run.
E flute
About 1.5 mm. Prints well and folds crisply; dents under a stack. Retail boxes, mailers and light shippers.
1.5 mm, single wallB flute
About 3 mm. The working default for parcels — takes print reasonably and stacks reasonably. Most shipping boxes are B.
3 mm, single wallC flute
About 4 mm. More cushioning than B, slightly less stacking strength per weight. Common on grocery and produce cases.
4 mm, single wallBC double wall
B and C glued together, about 7 mm. Heavy or fragile goods, pallet stacking, anything over roughly 15 kg.
7 mm, double wallKraft liner
Brown, strong, absorbent. One or two flat colors flexo print well on it; photographs drink into the brown and go muddy.
Outer and inner linerWhite top liner
A bleached outer liner for full-color print on corrugated. Costs more and marks more easily than kraft.
Outer liner onlyRecycled-content corrugated
High post-consumer fiber through liners and flute. The default for shippers; a slightly greyer brown and no loss of strength at grade.
All flutesCoated and water-resistant
A coating or a wax-free barrier liner for damp stores and cold chains. Check the recycling stream before printing a claim on it.
B and C fluteNot sure which? Say what goes in it and where it is sold — the material follows from that. Our notes on recycled, recyclable and compostable cover which claims each stock can honestly carry.
- 01
Send what you have
A dimension, a photograph beside a ruler, or the product itself. No technical drawing needed — that part is ours.
- 02
We quote and draw
A price, a dieline and a date come back together. If a different build would suit the product better, that is in the reply too.
- 03
Approve the dieline
The flat drawing is yours to check: which panel is the front, where the folds fall, how deep the cavity really is.
- 04
Artwork on the dieline
You place your design on the flat we sent, or we place it for you, and you see a proof before anything goes to press.
- 05
A sample if you want one
A plain unprinted sample at the finished size shows fit and construction — the things a drawing cannot.
- 06
Cut, printed, shipped
The die is cut once and kept, so every reorder skips the tooling and goes straight to press at a lower unit price.
Format
Vector PDF or AI where possible. Raster artwork at 300dpi at final size, in CMYK.
Bleed
3 mm past every trim line, so a fraction of drift on the cutter never leaves a white edge.
Safe area
Keep type and anything important 4 mm inside the cut and away from every fold.
Color
Convert to CMYK before sending. Uncoated stock prints lighter; a spot color is the only exact match.
Fonts
Outline them or supply the files. A missing font substitutes silently and the proof will not match.
Barcodes
On a light, matte, unvarnished patch with the quiet zone clear — a code on gloss fails the scanner.
Not set up that way? Send it anyway — fixing a file is a short conversation, and we check every one before press. Our guide to preparing print files covers each point.
Corrugated takes fewer finishes than folding board, and the ones it takes it takes well.
Flexo on kraft
One or two flat colors straight onto brown. Cheap, fast, honest.
Litho-lamination
An offset sheet glued to the flute: full color and photographs on a shipper.
Aqueous varnish
Scuff resistance with no film, so the box still recycles whole.
White top print
Full color flexo on a bleached liner; brighter, and it marks more easily.
Inside print
A second pass on the inner liner — the panel a customer sees first.
Printed tape seal
The brand applied at the last moment, on paper tape that recycles with the box.
Not sure which suits the shelf it sells from? Say where the product is sold and we suggest one — our notes on specialty finishes show them on real boxes.
Sizing a corrugated box against the carrier, not the catalog: foldable mailer boxes
Corrugated is cut to your internal size, so the box goes round the product rather than the product going into a stock size. That is where the money is: a box 20 mm smaller each way is often a whole postage band cheaper.
- Internal dimensions
- Length, width and depth of the space you need. Board thickness is added outside that, and the flute is thicker than people expect.
- Clearance and void fill
- 5–10 mm a side for a rigid product. Size it properly and you need no void fill at all, which is cheaper and better received.
- Stacking
- Tell us how high the boxes stack on a pallet or a shelf. Edge crush grade is specified from that, not guessed.
- Weight
- The contents weight sets the flute and the liner grade. Over about 15 kg we move to double wall.
- Score allowance
- Corrugated needs more room at the folds than boxboard. The dieline accounts for it; a box drawn from flat dimensions comes out tight.
- Cutting tolerance
- Plus or minus 1.5 mm on corrugated, wider than folding board because the flute compresses.
Not sure your numbers are right? Send the product dimensions rather than the box dimensions and we work the box out — the full method is in our guide to measuring for a box.
Interactive · five steps · no sign-up
Build your Foldable Mailer Boxes in 3D
Pick a shape, type a size, choose a board and a finish. The preview on the left redraws as you go, and the spec lands with us exactly as you set it.
Frequently asked questions
Got a question about foldable mailer boxes? The answers below cover what we get asked most. If yours is not here, send it with a brief, message us on WhatsApp, or call +1 503-461-4788 — we reply the same working day.
Does it need tape?
No. The corners lock into the base and the lid tucks into the front wall.
How fast does it fold?
Under ten seconds by hand, after the first few.
Can it be reused for a return?
Yes, it folds flat and locks again, and a second lock strip reseals it.
Is it strong enough to post on its own?
Yes, on E flute for most products and B flute for heavy ones or long journeys. The double walls give it more crush strength than a taped carton.
Can the inside be printed?
Yes, on the same pass as the outside.
What is the minimum order?
100 boxes.
How much space does it save?
About ten to one: a hundred flat blanks in the space of ten assembled boxes.
Can I have a tear strip?
Yes, on the lid, for a clean first open.
Kraft or white?
Kraft with one or two colors is cheapest; white for full color.
Do I need void fill?
Not in a box sized to the product plus 5–10 mm.
Is the die kept?
Yes, per size, so reorders and new print skip the tooling.
Do you ship outside the US?
Yes, to the United States, United Kingdom, Canada and Australia, quoted in the delivery currency.
Same range
