Panel saw layouts versus CNC nesting
Updated 29 September 2026
A panel saw and a CNC router cut the same sheet in different ways, so the optimiser has to plan them differently. The difference is less about saving sheets than about what your machine can actually cut.
Two kinds of layout
| Panel saw (guillotine) | CNC nesting | |
|---|---|---|
| How parts are separated | Straight cuts right across the sheet or strip | The cutter travels round each part |
| Layout rule | Every cut must run edge to edge | Parts can sit in any arrangement |
| Gap between parts | Blade kerf, 4.5 mm by default | Cutter diameter plus clearance, typically 10–14 mm |
| Shaped parts | Cut as rectangles, shaped afterwards | Cut to their real outline |
| Machining | A separate operation | Drilling and grooving in the same run |
Does nesting save sheets?
Less often than people expect. Nesting removes the edge-to-edge rule, which lets parts interlock, but a router needs a gap as wide as its cutter, and that gap is two to three times the kerf of a saw blade. For rectangular cabinet parts the two effects largely cancel out.
We ran three typical lists through both modes in Cutspan on 8x4 sheets — a set of drawer parts (60 pieces), two bookcases (18 pieces) and a mixed list of 37 panels — with a 4.5 mm kerf for the saw and a 12 mm gap for the router:
| List | Panel saw | CNC nesting | CNC, narrow parts tucked in |
|---|---|---|---|
| Drawer parts, 60 pieces | 2 sheets | 2 sheets | 2 sheets |
| Two bookcases, 18 pieces | 4 sheets | 4 sheets | 4 sheets |
| Mixed panels, 37 pieces | 3 sheets | 3 sheets | 3 sheets |
On all three the sheet count was the same. The layouts differed — the nested mixed list could not be cut on a saw at all — but the number of boards to buy did not.
When nesting is the right choice
- You own a CNC router and want parts cut, drilled and grooved in one run without handling them twice.
- Parts are shaped — curves, tapered sides, cut or rounded corners — and would otherwise be cut oversize on a saw and finished by hand.
- You want every part labelled in its position on the sheet for a machine file. See machine files.
- Many narrow parts can be tucked into gaps between larger ones; Cutspan’s Tuck narrow parts inside option does this for parts with a side under 200 mm.
When the panel saw is the right choice
- You cut on a panel saw, a beam saw or a track saw. A nested layout that cannot be cut with straight through-cuts is useless there.
- Parts are rectangles and machining is done separately, or not at all.
- Material is expensive and every millimetre of gap counts: a blade kerf wastes less than a router gap.
Choosing the mode in Cutspan
Open Cutting mode, cut width and trim below the parts table and choose Panel saw — straight cuts across the board or CNC nesting — tighter, needs a router. In nesting mode the gap is filled from the widest cutter in the job plus 2 mm; a number you type yourself is kept. Try both on your own list — it takes seconds, and your parts may behave differently from the examples above. More on gaps in saw kerf.
Questions
Is CNC nesting always more efficient?
No. On rectangular parts the wider cutter gap often cancels the freedom of the layout. Compare both modes on your own list.
Can a nested layout be cut on a panel saw?
Not in general. Nesting drops the rule that every cut runs edge to edge, so some layouts have no straight through-cut.
What gap should I use for CNC?
At least the cutter diameter, plus clearance. Cutspan suggests the widest cutter in the job plus 2 mm.
Does Cutspan give a cutting sequence for the saw?
No. It gives a layout that can be cut with straight cuts; the operator chooses a safe order.