Custom Box Partitions
A partition is the cheapest protective component in packaging and the one most often left out. It does not cushion anything. It simply guarantees that two hard objects cannot reach each other, which turns out to be most of what breakage prevention is.
- Formats
- Slotted partitions, die-cut inserts, wrap-arounds, celled layer pads
- Board
- Single wall B or E flute; solid board where the divider is seen
- Cells
- Cut 2–3 mm over the widest point of the item
Get a price for Box Partitions
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.
Glass against glass is the failure, not glass against box
A bottle striking a board wall is usually survivable. A bottle striking another bottle is usually not, because neither surface gives and the whole impact goes into two rims.
That is why a divider between every pair matters more than the strength of the box around them. It does not have to be strong; it has to be present, and it has to reach the full height of the contents.
A partition that stops short lets the necks meet above it. Cut it to the full height of the item, not to the depth of the box.
Slotted, die-cut or wrap-around
A slotted grid assembles from flat strips in seconds and flat-packs to almost nothing, which is why it has survived unchanged for a century.
| Slotted partition | Interlocking strips forming a grid; the classic bottle divider |
|---|---|
| Die-cut insert | One piece with cut-outs; better for irregular shapes |
| Wrap-around | A folded strip that separates a row; cheapest for two or three items |
| Layer pads with cells | For stacking layers of the same item in one case |
Board choice is about stiffness, not thickness
A partition works by resisting bending when something presses against it. Single wall B flute is far stiffer across a span than a solid board of the same thickness, so it holds a cell shape better under load.
For narrow cells or where the divider is visible in a gift build, solid board looks better and is adequate — the board behavior is set out in our flat board and layer pad notes.
Cell size, and the millimeter that matters
- A cell cut to the exact item diameter makes packing slow and awkward.
- Two or three millimeters of clearance lets the item drop in and still holds it.
- Too much clearance and the item moves inside its own cell, which defeats the point.
- Measure the widest point of the item — often a rim or a base flare, not the body.
It usually replaces something more expensive
Plenty of breakage problems get answered with foam, molded pulp or a bigger box when a few strips of board in the right place would have solved them for pennies.
It is worth trying the cheap answer first, on a real packed case, before committing to tooling. A partition costs almost nothing to test and is the quickest thing to change.
Box Partitions — 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
- Formats
- Slotted partitions, die-cut inserts, wrap-arounds, celled layer pads
- Board
- Single wall B or E flute; solid board where the divider is seen
- Cells
- Cut 2–3 mm over the widest point of the item
- Height
- Full height of the contents, not the depth of the box
- Supply
- Flat, assembles by hand in seconds
- Minimum
- 100 sets
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 box partitions 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: box partitions
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 Box Partitions 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 box partitions? 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.
Do partitions need to be strong?
Not especially — they need to be present, full height, and stiff enough not to bend under a knock.
How much clearance should a cell have?
Two or three millimeters over the widest point. Tighter is slow to pack; looser lets the item move inside its cell.
Corrugated or solid board?
Corrugated for stiffness across a span. Solid board where the divider is visible in a gift build.
Can a partition replace foam?
Often, yes. Test it on a real packed case first — it costs almost nothing and is the quickest thing to change.
What is the minimum order?
100 sets, flat and assembled by hand in seconds.
Should the partition reach the top of the item?
Always. A partition that stops short lets the necks meet above it, which is exactly the contact it was meant to prevent.
Do partitions need to be strong?
Not especially. They need to be present, full height, and stiff enough not to bend under a knock.
How much clearance should a cell have?
Two or three millimeters over the widest point. Tighter is slow to pack; looser lets the item move inside its cell.
Corrugated or solid board?
Corrugated for stiffness across a span. Solid board where the divider is visible in a gift build.
Can a partition replace foam?
Often, yes. Test it on a real packed case first — it costs almost nothing and is the quickest thing to change.
Same range
