Smart Components
Smart components allow for variation of design properties within a single component glyph. Each smart component can have its own set of variation properties such as width, height, angle, roundness, or any other arbitrary design feature that can vary along an axis. In this way, smart components work like multiple masters or a variable font, but with the variation axes exclusive to a component.
Smart components were initially designed for Asian scripts, where shapes are frequently reused with slight modifications, such as the strokes in CJK fonts or the components of the Tibetan script. This concept—reusable components with property variations—has proven useful for various scripts and glyphs.
Setting up Smart Glyphs
The glyph of a smart component is called a smart glyph. All CJK radical and Korean base glyphs are smart glyphs. In addition, all glyphs with a name starting with _smart. or _part. are smart glyphs.
The different forms of a smart glyph (for example, Narrow and Wide or Sharp and Rounded) are placed on smart layers. Click the plus button in the bottom-left of the Layers palette to create a new layer. New layers are named after the current date and time, but that is not a good description for a smart layer. Double-click the smart layer name and change it to a more descriptive one such as Narrow, Low Contrast, Small, or any other name that best describes the variation. For instance, for a _part.arrow glyph with a Width property, draw a normal arrow on the Regular master layer and a narrow version of the arrow on an additional layer aptly named Narrow. Note that smart layers need to be compatible with the master layer. For more on layer compatibility, see Outline Compatibility.
button in the bottom-left of the Layers palette to create a new layer.
New layers are named after the current date and time, but that is not a good description for a smart layer.
Double-click the smart layer name and change it to a more descriptive one such as Narrow, Low Contrast, Small, or any other name that best describes the variation.
For instance, for a _part.arrow glyph with a Width property, draw a normal arrow on the Regular master layer and a narrow version of the arrow on an additional layer aptly named Narrow.
Note that smart layers need to be compatible with the master layer.
For more on layer compatibility, see Smart glyph properties control how the smart component interpolates between the different layers. Add a property by opening the Smart Glyph Settings with Edit → Info For Selection (Cmd-Opt-I) or by choosing Show Smart Glyph Settings from the component context menu. It is split into two tabs: Properties and Layers.
Smart Glyph Properties Settings
Create a new property by clicking the plus button located in the bottom-left of the Properties tab. Smart glyph properties are similar to font axes. They have a name as well as minimum and maximum values. The name can be chosen freely and may be unrelated to the layer names or axes names of the font. The names Width and Height have a special meaning; see Width & Height Properties for details.
The minimum and maximum values can be any number range, but the minimum needs to be less than the maximum. Values can be negative. The default range of 0–100 works well for abstract properties such as Contrast or Curviness. If the variation property is less abstract and related instead to font units—such as Height or Descender Depth—consider using measurements as minimum and maximum values. Continuing the _part.arrow example, if the normal arrow is 855 units wide and the arrow on the Narrow layer is 375 units wide, add a Width property with a minimum of 375 and a maximum of 855.
Note that smart components can be interpolated and extrapolated. This allows the usage of values below the minimum and above the maximum. For example, a _part.arrow component with a Width property ranging from 375 to 855 can also be used with a Width value of 300 or 900. Extrapolation works well for simple variations such as the tail of an arrow getting longer and shorter, but might produce less desirable results for more complex smart components such as the arch of an n getting wider and narrower.
Use a minimum of 0 and a maximum of 1 for properties that should not interpolate and instead only be used as an on/off toggle.
Smart Glyph Layers Settings
The Layers tab connects smart properties with smart layers. The sidebar shows all smart layers of the glyph. Select a layer and set whether it belongs to the minimum or maximum value. If a layer is unrelated to a property, do not check any of the two values. For instance, for a glyph with two layers—Regular and Narrow—and a Width property, check the minimum Width value for the Narrow layer and the maximum Width value for the Regular layer.
A setup with multiple properties does not require a layer at all extremes. For example, a smart glyph with two properties—Width (range 375–855) and Height (range 80–360)—only requires the following three layers:
| Width | Height | |
|---|---|---|
| Regular | 375 | 80 |
| Wide | 855 | 80 |
| Tall | 375 | 360 |
Note that a layer at both maximum values (Width of 855 and Height of 360) is not required. Glyphs infers it from the Wide and Tall layers. Consider adding a layer at both extremes only if the inferred outlines are not as desired.
Using Smart Components
Add a smart component like any other component (as described in Building Composites). A smart component is indicated by a Smart badge in its Info box.
Smart Component dialog as shown with Edit → Info for Selection (Cmd-Opt-I) for a selected component.
If the Info box is not visible, select the smart component and check View → Show Info (Cmd-Shift-I). Click the Smart badge in the Info box or choose Edit → Info for Selection (Cmd-Opt-I) to configure the selected smart components.
If the Palette is visible (Window → Palette) and View → Show Info is checked, the smart component settings are also visible at the bottom of the Palette.
Use the slider to set the setting of a property anywhere from the minimum to the maximum value. Use the number field to input any value, which might also extrapolate beyond the minimum and maximum values. If the min/max values are 0/1, a checkbox is displayed instead.
to set the setting of a property anywhere from the minimum to the maximum value.
Use the number field to input any value, which might also extrapolate beyond the minimum and maximum values.
If the min/max values are 0/1, a checkbox 
is displayed instead.Width & Height Properties
Name smart glyph properties Width or Height (with a capital letter) to control them with the bounding box. Select View → Show Bounding Box (Cmd-Opt-Shift-B) and click on a smart component to show its bounding box. Resizing the bounding box horizontally changes the Width property; resizing vertically changes the Height property. Resizing the bounding box is impossible for a smart component with neither a Width nor a Height property.
Smart Handles
Left: Placing anchors with the names of properties on all layers. Right: Moving a knob to adjust smart settings.
Smart handles allow properties to be modified using control handles placed on the smart glyph. Place an anchor with the name of a smart glyph property on every smart glyph layer. The anchor names must match the name of the property exactly, including capitalization. On smart glyph layers affecting the property, move the anchor to match the modified outlines. These anchors do not need to be added for all properties.
When using the smart glyph as a component, gray handles will appear when the component is selected. Click and drag a handle to change its property value.