A Smart Component is a component reference with parameters. The referenced glyph defines one or more smart axes — for example Width or Weight — and carries alternate layers at extreme positions along those axes. The host glyph chooses values along each axis, and the component is rendered by interpolating between the alternates.

Use smart components for designed elements that vary independently of the rest of the font's masters: a serif that can be longer or shorter, a counter that can be wider, a stem that can be heavier — in places where wiring up a font master would be overkill or would not match the variation you actually want.

Smart Axes

Smart axes are defined on the referenced glyph. Each axis has a name, a numeric range (Min, Max), and a Default value. A glyph can have any number of smart axes. Add a smart axis through the Masters and Layers panel.

Alternate Layers

The master layer itself sits at one end of each smart axis — either its Min or its Max — and represents the shape at that extreme. Alternate layers cover the other positions along the axes. For a single Width axis, the master sits at one end of the axis and you add a single alternate layer at the opposite end; the editor interpolates between them. Alternate layers appear nested under their owning master row in the Masters and Layers panel.

Using a Smart Component

Reference a smart-component glyph from a host glyph the way you would any other component. Set the smart coordinates — the values along the component's smart axes — through the component's properties. Each reference can choose its own values, so two instances of the same smart component in a single host can render at different positions on its axes.

Anchors and Metrics on Smart Layers

A smart layer carries its own anchors and metrics, so both take part in the variation. Its anchors start as the glyph's own, read-only in the Anchors panel; edit one while the smart layer is active and it becomes that layer's anchor, the pole for that axis extreme. Select a smart layer in the Masters and Layers panel and the Glyph Properties panel shows and edits that layer's left and right side-bearings and advance width. Give the wide end of an emboldening axis a wider advance and the preview, the exported instances and, with Auto Attach, the host glyph's own advance follow it. In a multiple-master font this works per master.

The value editor that appears in the glyph editor when a smart component is selected (a slider and a number box per axis) accepts values outside the axis range, like the Variations panel.

File Format

Smart components are fully supported in the FontCreator project file, which preserves every feature of this release on save and load. They also round-trip cleanly through the .glyphs version 3 format: smart-axis definitions, per-master alternate layers, and the host's smart coordinates are all preserved.