Cutting, Slicing, and Erasing
Use Knife to insert points or divide paths, Scissors to construct overlaps and corner treatments, and Eraser to remove points or simplify a local section. These operations change the contour structure. Inspect the resulting paths and fill after each cut.
The Knife Tool
Press J or select Knife. Double-click its Toolbar button to open the toolbox. The three sub-tools determine what a drag through contours does:
| Sub-tool | Result along the cut line |
|---|---|
| Add nodes | Inserts nodes at intersections, leaving paths connected |
| Break contour | Inserts nodes and opens the paths at those positions |
| Slice contour | Divides the drawing into separate closed contours |
The Knife toolbox provides the cutting options for the active tool.
Repeated presses of J cycle the choices and return to the basic tool. With no sub-tool active, ordinary dragging adds nodes, Option/Alt-drag breaks, and Control-drag slices. On macOS the last gesture uses Control, not Command. With an explicit sub-tool selected, use that choice rather than relying on another modifier to override it.
Insert or duplicate a point
Click a segment to insert a node. Hold Shift while pointing near the segment to target an extremum or an inflection, where a curve changes its bending direction, then click to insert at the indicated position.
Clicking an existing node has a different result: it breaks the contour there. Shift-click the node to duplicate it in place while leaving the contour connected. Two coincident nodes can look like one, so inspect the result before adding more.
These click behaviors remain available across the Knife sub-tools; the selected sub-tool primarily changes dragging.
Cut along a line
Begin outside the outline and drag through the parts you want to cut. Hold Shift for a horizontal or vertical cut. Check the intersections indicated by the tool, then release.
Use Add nodes when you only need aligned insertion positions. Choose Break contour when the result should have open endpoints. Choose Slice contour when the pieces should each remain closed. Slicing between existing nodes can use those nodes as the cut endpoints.
Snapping and suggestions can influence the cut position; see Snapping and Suggestions. Inspect narrow parts and nearby contours so the line does not intersect more content than intended. Knife operations across compatible masters are covered in Editing across Masters.
The Scissors Tool
Press Q or select Scissors. Its toolbox offers Disconnect, Ink trap, and Loop corner. With all sub-tools off, plain gestures disconnect, Shift-click makes an ink trap, and Option/Alt-click makes a looped corner. A named sub-tool makes its operation available without those modifiers.
The Scissors toolbox groups cut modes with the numeric setting used by the selected mode.
Disconnect and make overlaps
Click a node with Disconnect to separate the junction into overlapping endpoints. FontLab can add fill behavior to retain the intended visible region, so inspect both the endpoint structure and the filled result.
Drag between nodes to split a junction into overlapping parts. You can also drag a marquee around two appropriate corner nodes for a simple overlap, or four concave corners for a crossing overlap. Choose a clear junction first; an arbitrary group of nodes need not produce a useful split.
This is a construction operation. It is useful when independent overlapping strokes are easier to adjust than a single outline around the whole letter.
Add a simple ink trap
An ink trap is a small notch at a junction of strokes. It opens a tight corner so that ink spread or small-size rendering is less likely to close it.
Choose Ink trap and click the intended corner, or Shift-click with the basic Scissors. The operation adds and separates points to form a small notch. The toolbox width starts from Font Info > Font Dimensions > Ink trap width; enter a different width in the toolbox for the current work.
The resulting simple ink trap consists of ordinary nodes. Adjusting the default later does not redesign this static notch. Live Smart Corner treatments are a separate way to retain adjustable corner behavior; see Smart Corners and Ink Traps.
Add a looped corner
Choose Loop corner, or Option/Alt-click with the basic tool. FontLab extends the corner's arms into a small self-intersecting loop while keeping the contour closed. Contour > Loop Corners applies this treatment to a selection, and individual nodes offer it in their context menu. Green cut feedback suggests a clean result; red warns of a potentially undesirable one. Inspect the geometry rather than treating the color as a guarantee.
Loop appearance and export handling depend on the current master’s Font Info > Font Dimensions > Unfill loops setting and the export profile; see Export Profiles. Do not assume every loop will disappear automatically. Check the filled result and an export before using the treatment throughout a design. A loop that remains part of the ordinary contour also affects point structure and interpolation requirements.
The Eraser and the Erasing Rectangle
Press 2 or select Eraser. Open its toolbox and choose the form of removal you need.
Remove points deletes nodes or handles under the circular cursor. Click one point or drag across several. Hold Shift to protect key nodes that FontLab identifies as important to the shape. Control-drag adjusts the erasing radius. Removing a point can change the curve even when the path remains connected.
Lasso eraser removes points inside a freehand enclosure. Draw around only the intended area and inspect the highlighted targets before finishing. Shift provides key-node protection here as well.
Simplify path works between two chosen nodes on the same contour, unlike the broader Simplify command in Structural Soundness. Click the first, then the second, to reduce the intermediate structure. Compare the resulting span with the original, especially on a closed contour where there are two possible routes between the endpoints.
In the basic Eraser state, Option/Alt-click can remove a segment or break around a node, leaving an open path. Use the explicit Knife Break operation if an opening, rather than point removal, is your main intention.
For a rectangular cutout, select Erasing rectangle in the Rectangle tool group. Drag across the region to subtract; hold Shift for a square or Option/Alt to draw from the center. This removes geometry and resolves the cut. It does not place a white rectangle over the drawing.
After erasing, switch to the Contour tool and inspect the remaining nodes, closure, and corners. Undo an overly broad cut before making further edits that would make the original geometry harder to recover.
Live fill alternatives are covered in Boolean Assembly: Fusion, Clipping, and the Fill Tool.