How to reduce waste
Waste is decided before the first cut: by the sizes you choose, the settings you give the layout and what you put on the same sheets. This guide changes one thing at a time on the same job and shows what each change is worth.
The baseline
Three 600 mm base cabinets, 21 parts, on 2440 × 1220 mm sheets with a 3 mm kerf, 10 mm trim and rotation allowed. The layout needs 4 sheets, and 34.5% of the board is not parts.
| Part | Width (mm) | Height (mm) | Qty |
|---|---|---|---|
| Side | 560 | 720 | 6 |
| Bottom | 564 | 560 | 3 |
| Top | 564 | 560 | 3 |
| Shelf | 564 | 540 | 3 |
| Back | 600 | 720 | 3 |
| Door | 596 | 716 | 3 |
Layout produced by CutGrid’s optimizer for this example. Coloured blocks are parts, dashed areas are offcuts, and the outer band is trim.
- Side
- Bottom
- Top
- Shelf
- Back
- Door
1. Trim only what is damaged
Trim removes a strip from every edge before parts are placed. With 10 mm of trim the job needs 4 sheets. With clean factory edges and trim at 0 it needs 3 sheets at 12.6% waste.
Look at the edges you actually get. Square, undamaged melamine often needs no trim; sheets stored on edge in a yard usually do.
Layout produced by CutGrid’s optimizer for this example. Coloured blocks are parts, dashed areas are offcuts, and the outer band is trim.
- Side
- Bottom
- Top
- Shelf
- Back
- Door
2. Let parts rotate
Locking rotation for every part, as if every part had grain, pushes the job to 5 sheets at 47.6% waste. Lock only the parts whose grain or pattern must run one way, and leave the rest free.
3. Choose the sheet size
On 2800 × 2070 mm board the same job needs 2 sheets and buys 11.59 m² instead of 11.91 m². Whether that is cheaper depends on the price per sheet; the sheet sizes guide compares three formats.
4. Cut jobs together
A 1800 mm bookcase on its own needs 2 sheets. Laid out together with the cabinets, both jobs need 5 sheets, because the bookcase parts fill gaps the cabinets leave. If two jobs use the same board, lay them out as one list.
| Part | Width (mm) | Height (mm) | Qty |
|---|---|---|---|
| Side | 300 | 1800 | 2 |
| Top/bottom | 764 | 300 | 2 |
| Shelf | 762 | 280 | 4 |
| Back | 800 | 1800 | 1 |
| Job | Sheets |
|---|---|
| Three cabinets | 4 |
| Bookcase | 2 |
| Both in one layout | 5 |
5. Keep the offcut
Every plan ends with offcuts. The largest from the baseline is 1853 × 1200 mm. Save it to the stock library and add it to the next job’s stock, and part of this job’s waste becomes the next job’s material. The offcuts guide shows a remnant being used before a new sheet is opened.
Common mistakes
Changing settings to make the number look better
Kerf 0 or trim 0 on a damaged sheet gives a nicer plan and parts that do not fit. Use the real values.
Laying out one cabinet at a time
Each cabinet ends with its own offcut. One list for the whole job shares those gaps.
Throwing offcuts away
An offcut is only waste if nobody uses it. Label it with its material and size, and store it flat.
Questions
- What is a good waste percentage for sheet goods?
- It depends on the parts. This one job ranges from 12.6% to 47.6% depending only on settings. Compare plans for the same job, not percentages across different jobs.
- Does a better optimizer reduce waste?
- It finds better layouts for the same inputs, and the difference can be a sheet. The bigger levers are usually the inputs: trim, rotation, sheet size and combining jobs.
- Is waste the same as offcut?
- In CutGrid, waste is all bought board that is not a finished part: offcuts, trim and kerf. Offcuts are the part of it you can reuse.