FIELD NOTES / THE CUTTING ROOM
Leave room
for the blade.
A sheet layout is useful only when the drawing reflects the material you actually have. Three easy-to-miss details—blade width, clean edges and grain direction—can turn an apparent fit into a second sheet.
Start with finished part sizes
List each distinct rectangle with its width, height and quantity. Use one unit throughout: millimeters or decimal inches. PanelNest converts dimensions when you switch units, including your part sizes, blade kerf and edge trim. It does not accept fractions such as 3/8; enter 0.375 instead.
Plan one material and thickness per job. If you need excess material for sanding, machining or a later trim, add that allowance to the sizes you enter. The planner does not infer allowances or edge banding.
Why four squares might need four sheets
Imagine four 50 × 50 mm parts and 100 × 100 mm stock. With zero kerf and no trim, the four squares exactly fill one sheet. With a 3 mm blade, a pair needs 50 + 3 + 50 = 103 mm. Neither direction can fit two pieces, so each square needs its own sheet in this example.
Change the parts to 48 × 48 mm and use a 4 mm kerf. Now a pair needs exactly 100 mm. Four parts fit one sheet: 9,216 mm² of finished parts and 784 mm² of blade loss, with no remaining area. These are geometry examples, not recommended blade settings.
Reserve clean edges before nesting
Edge trim applies to all four edges. A 2440 × 1220 mm sheet with 10 mm trim has a usable rectangle of 2420 × 1200 mm. The layout starts at coordinate (10, 10), measured from the original sheet’s top-left corner. The outer trim is accounted for separately from the internal cut references.
Lock the grain before rotating parts
PanelNest treats the grain direction as running along sheet width. Part width aligns with that direction when rotation is off. Allow a 90° turn only where it is suitable for the material and your finished design. To represent stock whose grain runs along its other dimension, swap the entered sheet width and height.
The planner does not infer which faces will be visible. A rotated part may fit better but still be wrong for a furniture design. Inspect the grain rules on every distinct part.
Read the material totals
| Measure | Meaning |
|---|---|
| Utilization | Finished-part area ÷ purchased sheet area × 100 |
| Blade loss | Area removed by the internal separation cuts |
| Edge trim | Area reserved around the stock perimeter |
| Offcuts | Remaining, non-overlapping rectangles in the layout |
These areas add back to the purchased area. The standard sample has 2.136 m² of finished parts on a 2.9768 m² sheet, or approximately 71.8% utilization. Tiny offcuts can be geometrically valid without being useful to keep.
Understand the search method
The planner tries six part orderings with two placement strategies. Every layout uses rectangular guillotine splits: a cut divides the current rectangular region across its full width or height. It selects fewer sheets first, then a larger remaining offcut, then shorter internal cut references.
This heuristic is deterministic: the same inputs give the same result. It does not prove a mathematical optimum. Different packing algorithms or an experienced maker may find a better layout. It assumes unlimited identical new sheets and does not account for defects, clamps, machine travel, existing offcut inventory or irregular shapes.
Take the right export
- Print plan / PDF: all sheets with their dimensions and grouped parts. Use written dimensions; the diagram scales to the page.
- Sheet SVG: a visual drawing for the selected sheet. It is not a full-scale cutting template or a toolpath.
- Part CSV: every placed part with sheet, orientation and coordinates, plus any unplaced pieces.
- Job JSON: a reusable backup of your inputs. Use Open job to restore it.
- Offline Workshop DXF: selected sheet and finished-part outlines with a bottom-left origin. Check units and scale in CAD/CAM. No blade compensation, machining passes or toolpaths are generated.
Check dimensions, material, grain, defects and a safe cutting sequence before cutting. Internal cut references describe the already trimmed sheet; they do not replace machine-specific setup or workshop judgment.
A small import example
CSV rows use these five columns. Quote names containing commas. Use yes or no for rotation:
name,width,height,quantity,rotate
Side,760,400,4,no
Shelf,760,250,2,no
Divider,450,300,4,yesNeed to estimate broader material and labor costs? Try CraftCost. Make simple finishing labels with LabelLeaf.