Nesting brings to mind a single button in a CAM package: drop in the parts, click "arrange", get a sheet. In practice most of the waste and most of the complaints are born before that button, in decisions about format, direction, spacing and order. Below are six rules we apply when preparing production files for spatial branding and interior fit-out.
1. Sheet format first, design second
Furniture board, plywood, dibond and acrylic come in different trade formats with different usable sizes once the edges are trimmed. A design created without knowing the target format almost always ends with a part 12 mm too long to fit twice on the sheet. Before you draw the first line, settle: which material, which format, and how many sheets the fabricator actually has in stock.
2. Grain and print direction are not optional
Plywood, wood-effect laminates and anything printed have a direction. Rotating parts by 90° can give you a few percent better yield, but on the finished piece every panel running against the grain shows. Lock rotation wherever direction matters and allow it only for hidden parts.
3. Spacing measured from the cutter, not by eye
The gap between parts is the tool diameter plus a safety margin for vibration and hold-down. For a 6 mm cutter in 18 mm board we usually leave 10 to 12 mm; for a laser in acrylic a few millimetres will do. A nest that is too tight looks great in CAM and ends with a part shifting halfway through the toolpath. Common-line cutting only makes sense on a laser and only on straight edges.
4. Large parts first, small parts fill in
Nesting order: full-size parts, then medium, and finally the small stuff into the gaps. Start with the small parts and the sheet fills up in fragments, the large part lands on a new sheet, and the remnants of the previous one go in the bin. This is the most common cause of the difference between 70% and 85% material utilisation.
5. An offcut is material, not waste
If a strip of sensible width is left on the sheet, plan the cuts so the remnant is a single rectangle rather than a jagged outline. A rectangular offcut gets shelved by the fabricator and used on the next job. A jagged one gets thrown away. This rule sometimes means deliberately giving up a point or two of utilisation on the current sheet, but it pays off over a month.
6. Validate before release, not after cutting
The most expensive mistake is not a bad nest but a bad file. Before the package goes to the shop floor we always check the same things:
- layers: through-cuts, pocketing, engraving and labels on separate, unambiguously named layers,
- closed contours, no duplicate lines and no zero-length segments,
- units and scale (millimetres, 1:1) and the sheet origin,
- part labels consistent with the cut list and the assembly drawing,
- quantity per part consistent with the BOM, mirrored parts included.
Only after this list does the file get a version number and go to production. In our process one hundred percent of files pass this verification, and a typical production package ships within 24 to 48 hours of design sign-off.
Summary
Good nesting starts with the question "what will this be cut on and from what" and ends with a release checklist. The arrangement algorithm sits in the middle and, honestly, matters least.
If you need a production package prepared for your workshop or subcontractor, see production support.
