Settings & Kerf
The Settings panel controls the parameters that shape how CutOptim runs its optimization. Getting these right — especially kerf width and cut type — has a direct impact on result accuracy and whether the cut plan will work in practice.
Open Settings by clicking the gear icon in the top-right toolbar, or press Ctrl +, .
Kerf Width
Kerf is the width of material removed by each saw cut. Every time a saw blade passes through material, it converts a thin strip of material into sawdust. For a job with many cuts, this accumulated waste is significant.
Why kerf matters in optimization:
Consider cutting a 2440 mm sheet into pieces of 600, 600, 600, and 600 mm:
- Without kerf: 4 × 600 = 2400 mm needed → fits with 40 mm leftover
- With 3 mm kerf: 4 × 600 + 3 × 3 = 2409 mm → still fits, but with only 31 mm leftover
- If there were 5 pieces: 5 × 600 + 4 × 3 = 3012 mm → does NOT fit on a 2440 mm sheet
An incorrectly entered kerf value can cause CutOptim to produce layouts that are physically impossible to cut.
Kerf Reference by Tool and Material
| Tool | Material | Typical kerf |
|---|---|---|
| Table saw (full kerf blade) | Wood, sheet goods | 3.0–3.2 mm |
| Table saw (thin kerf blade) | Wood, sheet goods | 2.4–2.6 mm |
| Track saw / circular saw | Wood, sheet goods | 2.6–3.2 mm |
| Panel saw / beam saw | Wood, sheet goods | 3.2–4.0 mm |
| Angle grinder (cutting disc 1mm) | Steel, aluminium | 1.0–1.5 mm |
| Angle grinder (cutting disc 2mm) | Steel | 2.0–2.5 mm |
| Cold saw | Steel, aluminium | 1.5–3.0 mm |
| Laser cutter | Steel, acrylic, wood | 0.1–0.5 mm |
| CNC router (straight bit) | Wood, aluminium, acrylic | 3.0–8.0 mm |
| Water jet | Steel, stone, glass | 0.8–1.2 mm |
| Glass saw / wheel | Float glass | 0.5–1.5 mm |
| Band saw | Wood, metal | 1.5–3.5 mm |
Always measure your actual kerf rather than assuming a standard value. Blade wear, material hardness, and feed speed can all affect the actual kerf width. A simple way to measure: make a cut in a scrap piece, then measure the width of the cut with a dial calliper.
Units
CutOptim supports two unit systems:
| Setting | Description |
|---|---|
| Millimetres (mm) | Default. Recommended for woodworking, metalworking, and glazing in metric regions. All dimensions entered in mm. |
| Centimetres (cm) | Recommended when working with larger timber or construction materials where mm precision is unnecessary. |
Imperial units (inches, feet) are on the roadmap. If your workflow requires imperial dimensions, enter measurements as their mm equivalent (1 inch = 25.4 mm) or use cm as an approximation.
When you switch units, all existing values in the Stock and Demand tables are converted automatically. The conversion is exact (no rounding errors) for values entered in whole millimetres.
Cut Type
Cut type controls the algorithm CutOptim uses to arrange pieces on sheets. This setting is only relevant for 2D Panel Cutting — 1D and Wood modes always use a linear algorithm.
Guillotine
In guillotine mode, every cut extends from one edge of the remaining material to the opposite edge. This models the real physical constraint of a table saw, panel saw, beam saw, or track saw — where lifting the blade mid-cut is not practical.
Characteristics:
- Lower theoretical maximum yield (typically 85–93%)
- Cut sequences can be handed to a manual operator
- PDF export includes a numbered cut sequence
- Realistic for all manual and semi-automatic cutting environments
How guillotine cuts work:
After each guillotine cut, the material is divided into two rectangles. Subsequent cuts can be made on either of these sub-rectangles, again edge to edge. This creates a binary tree of cuts, which is why the PDF can list them as Step 1, Step 2a, Step 2b, etc.
Nested
In nested mode, pieces are placed into any available free rectangle on the sheet without the guillotine constraint. A CNC router or laser cutter can start and stop a cut at any point, so there is no need to cut edge to edge.
Characteristics:
- Higher theoretical maximum yield (typically 88–97%)
- Cut paths are not always human-readable as a sequence
- DXF and SVG exports are particularly useful in this mode
- Required for CNC / automated cutting machines
A useful rule: if you can make all the cuts shown on the plan using only a table saw or panel saw without rotating the sheet, use Guillotine mode. If you need a CNC router to achieve the layout, you are in Nested territory.
Minimum Offcut Size
The minimum offcut size defines the threshold below which a leftover piece of material is treated as waste rather than a reusable offcut.
| Feature | Type | Description |
|---|---|---|
| Minimum offcut width | number | In 2D mode: the minimum width of a remaining rectangle to qualify as an offcut. |
| Minimum offcut height | number | In 2D mode: the minimum height of a remaining rectangle to qualify as an offcut. |
| Minimum offcut length | number | In 1D and Wood modes: the minimum length of a remaining bar section to qualify as an offcut. |
Recommended minimum offcut sizes by trade:
| Trade | Recommended minimum (2D) | Reasoning |
|---|---|---|
| Cabinet making | 200 × 200 mm | Small panels have practical uses (drawers, doors, shelves) |
| Glass cutting | 300 × 300 mm | Smaller glass pieces are typically unsafe to handle and store |
| Sheet metal | 150 × 150 mm | Small offcuts useful for brackets and patches |
| Signage / display | 100 × 100 mm | Small pieces usable for letters, mounts |
For 1D / Wood mode, a minimum of 200–500 mm is typical, depending on the material. A 150 mm steel bar offcut is rarely worth storing; a 500 mm timber offcut often is.
Setting the minimum offcut size too small can clutter your offcut inventory with tiny pieces that are never actually used. Setting it too large will cause genuinely useful pieces to be counted as waste. Review your inventory periodically and purge pieces that have never been used.
Advanced Settings
Click Advanced Settings in the bottom of the Settings panel to reveal additional controls. These options are collapsed by default to keep the interface clean for everyday use.
First Cut Direction
The first cut direction controls which axis is cut first on a 2D sheet in Guillotine mode. It has no effect in Nested or 1D/Wood modes.
| Feature | Type | Description |
|---|---|---|
| Auto ⚡ | option | The optimizer decides whether the first cut should be horizontal or vertical, choosing whichever produces better yield. Recommended in most cases. |
| Horizontal ↔ | option | The first cut always runs left-to-right across the sheet. Use this when your cutting machine has a maximum vertical dimension (e.g. a panel saw with a fixed fence height). |
| Vertical ↕ | option | The first cut always runs top-to-bottom. Use when your machine has a maximum horizontal dimension constraint. |
Leave this on Auto unless your cutting machine has a specific directional constraint. The Auto mode tests both orientations and picks the best one — locking a direction can reduce yield by 1–3%.
Currency
The currency selector sets the symbol and format used in cost calculations, the results summary, and quotation PDF exports.
Available currencies: EUR (€), USD ($), GBP (£), HUF (Ft), RON (lei), PLN (zł), CZK (Kč), CHF (Fr)
The currency setting is stored per project. Changing it does not convert any entered prices — it only changes the symbol displayed next to the values.
Optimization Goal Pro
The optimization goal lets you choose what the algorithm prioritizes when arranging pieces.
| Feature | Type | Description |
|---|---|---|
| Minimize waste 📉 | option | The algorithm tries to maximize yield — getting the most usable material out of the fewest sheets or bars. This is the default and is appropriate for most jobs. |
| Minimize cost 💰 | option | The algorithm considers the price of each stock item and arranges pieces to minimize total material spend. Useful when you have stocks of very different unit prices and want to favour cheaper sheets. |
Minimize cost requires prices to be entered in the Stock table. If no prices are entered, both goals produce identical results. Enable Detailed Cost Entry (below) to add price columns to the tables.
Detailed Cost Entry Pro
Detailed Cost Entry adds a price (💰) column to both the Stock and Demand input tables, enabling per-item pricing for cost calculations and quotation export.
Enabling it:
- Open Advanced Settings
- Toggle Detailed Cost Entry on
- A 💰 column appears in the Stock table (price per sheet/bar) and the Demand table (price per piece)
- Enter unit prices as needed
- Prices flow automatically into the results cost summary and the Quotation PDF export
This toggle is off by default to keep the tables uncluttered. Enable it only when you need cost calculations or are preparing a quotation. The toggle state is saved per project.
Default Settings
When you create a new project, it inherits the global default settings. You can update global defaults from the Settings panel:
- Open Settings ( Ctrl +, )
- Configure your preferred values
- Click Save as Default
From this point, all new projects start with your preferred kerf, units, cut type, and minimum offcut size. Existing projects are not affected.