What Gridfinity gets right
Gridfinity — Zack Freedman's open standard for 3D-printed storage — works because it fixes the unit. Every bin is some multiple of 42 mm, every baseplate is a grid of those units, and so anything fits anywhere. It's the first small-parts system that's genuinely modular rather than “modular” in the marketing sense.
The side effect is that people make a lot of bins. Bins are cheap, printing is fun, and the drawer looks amazing. And then you have 200 bins that all look the same from the top and a growing suspicion that the M3 heat-set inserts are “somewhere on the left”.
The missing layer: a map that speaks Gridfinity units
Because Gridfinity is a grid, it maps perfectly onto a grid-based inventory. A drawer with a 6 × 4 baseplate is a 6-column × 4-row layout. A 2 × 1 bin is a merged cell. A 1 × 1 bin is a single cell. If you can describe the drawer in Gridfinity units, you can describe it exactly in WhichDrawer — no approximation, no “misc” cells.
- Photograph the drawer from directly above. Good light, drawer fully open. This becomes the organizer's cover.
- Draw the baseplate grid (6 × 4, 8 × 5, whatever you printed) and merge cells to match your larger bins.
- Add what's in each bin as an item with a photo. Bins that hold several part sizes get several items with per-bin quantities.
- Search by photo when you can't name it. Hold the mystery hex standoff up to the camera; the app returns the closest matching item and its bin.
Layout tools + inventory
If you planned the drawer in a Gridfinity layout tool, you already have the grid — recreate it in WhichDrawer in a minute (custom layouts go up to 12 × 12; bigger baseplates can be split into two organizers, left half / right half). We're exploring direct import from popular layout tools; if you'd use that, tell us which one.
Bin labels vs. a searchable index
Gridfinity has a fantastic label ecosystem — click-in labels, embossed lids, printed tags. Use them. But labels answer “what is in this bin?” when you're already standing at the drawer. An index answers the harder question — “which drawer, and which bin?” — from the other end of the shop, or from the hardware store when you can't remember whether you already have M4 × 12 socket heads. Low-stock alerts on the consumables (inserts, magnets, filament swatches) are the cherry on top.
A note on Multiboard, HSW and other systems
Everything above applies to any grid-based system: Multiboard bins, Honeycomb Storage Wall, Alexandre Chappel's assortment boxes, or plain Akro-Mils cabinets. If it's a grid, it maps. See the Drawer Organizer Guide for grid dimensions of common commercial cabinets.
WhichDrawer is free for one organizer — enough to map your first Gridfinity drawer and decide whether the missing layer was worth adding.