Designing with Skeletons

A contour can describe the path a pen travels instead of the boundary of the ink. Give that path a thickness and FontLab generates the visible outline around it. This is skeleton-based design: you edit the structural path of a letter or symbol and control how much body it receives.

A skeleton is the centerline or guiding path of a stroke-built form. An open contour is a natural skeleton for a stem, swash, or handwritten stroke. A closed path can also guide a stroke, for example around a ring. The generated ink has an outline of its own, distinct from that source path.

This changes what you draw first. To make a monolinear symbol, you can draw its path and choose a thickness rather than constructing both sides separately. To shape a calligraphic stroke, you can adjust the movement of its skeleton and the pen that follows it. The outline is generated from those decisions.

FontLab offers two approaches:

• Stroke offsets the path to form its sides. You control thickness, its distribution on either side, the caps at open ends, and the joins at corners. A uniform stroke has no inherent broad-nib contrast.
• Brush carries an elliptical nib along the path. The nib's shape and angle produce thick and thin regions as the path changes direction. A circular nib gives even thickness; a narrow, angled nib gives calligraphic contrast.

Both approaches let you establish a form with relatively few skeleton nodes. They suit monolinear and stencil lettering, script and calligraphic faces, symbols, and icon fonts. They can also help construct strokes for Arabic or CJK designs. The usefulness comes from the particular design: a skeleton can organize repeated strokes, but it does not supply the script's proportions, joins, spacing, or stylistic rules automatically.

Thickness can remain adjustable as the design develops. Try a heavier setting on the same skeleton, then inspect counters, joins, and spacing. A different weight may still need changes to the path or local thickness. One global value does not guarantee an optically finished family.

There are several ways to retain or commit that editability. A simple stroke remains an adjustable element property until expanded, though its generated edges are treated as a decoration during editing. Power Stroke promotes those edges to interactive virtual geometry while retaining the skeleton. Power Brush similarly keeps a live skeleton-and-nib construction. The Simple brush drawing mode instead creates a finished outline from each gesture, which you then edit as ordinary contours.

Keep the live construction when changes to path, thickness, or nib will remain useful. Expand it when you want to edit the generated outline directly. Save a native working version before expansion if you may need to return to the skeleton. Production export resolves supported live constructions into the final geometry.

Local modulation lets a skeleton-based form swell or taper instead of remaining uniform. With a stroke, you can adjust its two sides independently. With a Power Brush, you can adjust the nib along the path. These controls give you more detail without requiring you to redraw the entire outline.

Stroke and brush are not confined to open skeletons. A closed filled shape can carry an additional stroke around its boundary, a useful arrangement in color work; see Coloring Contour Elements. The same geometry controls apply, although the fill and stroke then have separate visual roles.