Custom Postal Boxes
Custom postal boxes from 100 — thin, kraft corrugated mailers sized to slip under a carrier’s cheapest parcel band and, where it suits, through a front-door mail slot, so the order arrives without a missed-delivery card.
Sized to the mail slot, priced to the rate band
- Board
- E flute kraft corrugated; B flute for heavier contents
- Styles
- Roll-end front tuck, book wrap, slim lid-and-tray, crash-lock base
- Sizes
- Set to your carrier’s parcel and large-letter bands
Get a price for Postal 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.
Measurements that set the postage
- Depth kept to the limit your carrier sets for its smallest parcel or large-letter band.
- Length and width sized so the box does not cross into a larger dimensional band.
- Board chosen light enough that box plus product stays under the next weight break.
- For door delivery, a depth that clears a standard mail slot.
Postal box styles
| Roll-end front tuck | The everyday kraft mailer, lid tucks in at the front |
|---|---|
| Book wrap | Folds around a flat item, for books, prints and planners |
| Slim lid-and-tray | Two parts, for products that need to sit deep |
| Crash-lock base | Locks square in one push, for faster packing |
Kraft, plain or printed
Most postal boxes go out in natural brown kraft, which hides scuffs from the sorting belt. A one-color logo on the lid is enough for many shops; others print the inside and leave the outside plain so the parcel looks anonymous in transit. If packing time is the problem, our mailers with a peel-and-seal strip add an adhesive closure to the same postal sizes.
Surviving the sorting machines
Thin parcels are pushed, flipped and dropped by sorting equipment, and a box that crushes at one corner opens its seams. E flute is the usual choice: thin enough for low profiles, rigid enough to keep its shape. For heavier items, a B flute body with an E flute lid keeps the strength where it is needed. We test-fold the size with your product before printing.
Postal 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 corrugated; B flute for heavier contents
- Styles
- Roll-end front tuck, book wrap, slim lid-and-tray, crash-lock base
- Sizes
- Set to your carrier’s parcel and large-letter bands
- 1–2 color flexo outside, full color inside on request
- Closure
- Tuck flap; peel-and-seal strip optional
- Packing
- Flat, banded in bundles
- 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 postal 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 grayer 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: postal 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 Postal 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 postal 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.
What makes a postal box different from a regular mailer?
Its size is set by the carrier’s rate bands and mail-slot limits first, then fitted to the product.
Can a postal box fit through a mail slot?
Yes, if its depth is kept to the slot limit. We size it to the depth your carrier or market uses.
Which board is best for postal boxes?
E flute kraft for most items. B flute suits heavier contents that would crush a thin box.
Can you size postal boxes to stay under a weight break?
Yes. We choose the lightest board that still protects your product, so box plus contents stay under it.
Are printed postal boxes much more expensive than plain?
A one-color flexo logo adds little. Full-color print inside costs more and is quoted separately.
Do you make book wrap postal boxes?
Yes, for books, planners and prints. The board folds around the item and holds it flat.
Can postal boxes have a peel-and-seal strip?
Yes, added to the front tuck, so the box closes without tape.
Will a kraft postal box survive sorting machines?
E flute keeps a low box rigid through sorting. We test-fold your size with the product before print.
Can the inside of a postal box be printed instead of the outside?
Yes. Many shops print inside only so the parcel looks plain in transit.
What do you need to quote postal boxes?
The product size and weight, the carrier you ship with, and whether you want mail-slot delivery.
What is the minimum order for postal boxes?
100 boxes per size, so a shop can trial one size before stocking a range.
Same range
