Board game insert generator: cut plan and STL

What an insert is

An insert, or organiser, is a set of trays that sits inside the box. It keeps parts apart and, more importantly, cuts setup and teardown time. The number it sells is setup time, not looks.

There are two ways to build one. Cut foam board with a hobby knife, or print it. Foam board is cheap and needs no machine. Printing is precise and repeatable. This tool produces both from the same input.

This tool holds no game data. There is no lookup by game name. You measure your own box and your own components. That is why it works for any game, and why you need a ruler.

Measuring

Measure the inside, not the box art. Walls and internal ribs make the usable space much smaller than the outside.

• Take width and depth at the narrowest point, past any ribs.
• Take height from the floor to where the lid actually rests. A lifted lid means the box will not close.
• For components, measure one piece. For cards, measure one card, not the stack.
• If the cards are sleeved, measure them sleeved, or pick a sleeve size below.

Use a steel rule. A tape measure bends in the corner and costs you 1 to 2 mm. When a reading is between two values, write the smaller one. The box will not stretch.

Sleeve sizes

Source: BGG Card Sleeve Reference, Gamegenic Sleeve Size Guide 2022 (checked 2026-09-21). These are sleeve outer sizes. Sleeved stack thickness varies by brand, so it is not listed. Measure your own stack.

How this tool behaves

Three markings decide the trays

Every component gets one marking. That marking is the whole layout rule.

• Split per player: the count is divided by player count and you get one identical tray each.
• Taken out once at setup: placed last, so it ends up on the top layer and at the edges.
• Used all game: placed first, so it sits at the front where your hand goes.

Counts that do not divide evenly are not dropped. The remainder goes to a shared slot and the screen says how many.

How a slot is sized

Add the clearance to one piece. Then raise the number of pieces per layer from 1 until the resulting stack height fits the box depth, and spread that number over the closest thing to a square. Stacking wins because it uses less floor. Tray outer size is the box inside size minus 2mm, so the tray does not bind.

If it does not fit, it says so

Clearances are never quietly shaved. You get the component, the axis, what is needed and what is available. Reduce the material thickness, reduce the clearance, or move that component to another marking.

The setup order comes from the layout

Steps 1, 2, 3 are derived, not written by us. Top-layer trays come out first, per-player trays get handed out, all-game trays stay in the box. If a group is empty, that line does not appear.

The design lives in the URL

Copying the design link compresses the whole design into the URL fragment. Browsers never send that part to a server, so our server does not see it. No account, no storage.

What this tool does not do

No lookup by game name, no downloading other people's STL files, no finger joints, no curves or rounded corners, no lids or magnets, no undo, no design library.

Building it in foam board

You need foam board, a hobby knife, a steel rule and wood glue. Snap the blade often. A dull blade tears foam instead of cutting it.

Butt joints only

A knife cannot cut finger joints, so every joint is a butt joint and one rule is fixed: the floor panel covers the whole base, walls stand on top of it, the front and back walls run full width and the side walls fit between them.

• Floor: tray width x depth, 1 piece
• Front and back: width x (height - thickness), 2 pieces
• Sides: (depth - 2 x thickness) x (height - thickness), 2 pieces
• Dividers: between rows and within a row

Assembled, the outside comes out exactly at the tray size. A golden test re-derives it from the cut pieces on every run.

Printing and cutting

The PDF is 1:1. Print at 100%, no scaling, or every dimension is wrong. Sheets larger than the paper are split across pages with a 10mm overlap, marked with a dashed line and a row and column label. A 10mm margin is left blank because most home printers cannot reach it.

Pieces are laid out 2mm apart for the kerf. Spray-tack the printed sheet onto the foam board and cut along the lines. Three light passes beat one deep one. A 1mm cutting error stays inside the clearance.

Glue-up order

Lay the floor, stand the front and back, fit the sides between them, then drop in the dividers. Spread the glue thin. Too much glue soaks the foam and it warps. Let it sit an hour, then load the components one group at a time.

Printing it

Pick 3D print as the material and you get one STL per tray in a zip. Walls are 1.6mm and the floor is 1.2mm. Those are constants, not screen settings.

• Enter your build plate side and tray footprints stay inside it. Oversized designs split into more trays.
• No supports needed. Every wall rises straight off the plate.
• 0.2mm layers, two perimeters and 10% infill are enough.
• Wide flat bottoms warp. A brim keeps the corners down.

The files are standard binary STL: an 80-byte header, a triangle count, then 50 bytes per triangle. One box is 12 triangles. Overlapping walls are fine because the slicer merges them.

When you get stuck

It says it does not fit

Read the axis. Short on height means too many layers, so cut setup-only components or reduce clearance. Short on width or depth means one component is wider than a tray, so try a thinner material.

The cards do not go in

Sleeved cards are bigger than the bare size. Pick a sleeve size or measure them sleeved. In the height field enter one card, about 0.3mm. Entering the stack makes the slot far too deep.

The printed plan measures wrong

Check the print scale. Anything other than 100% is wrong. Verify it by putting a rule on one labelled edge: 100mm should read 100mm.

My design is gone

A reload clears the form. Copy the design link and reopen that URL to carry on. Only the setup timer is stored on this device.

Do my dimensions leave the browser

No. The server receives a step name and the UI language. Open the receipt at the bottom of the front page to count what this page requested, host by host.