The Axes tab is only used with variable fonts.

Axes

The most common registered axis is the weight axis, but there are several other registered axes and numerous unofficial axes.

Registered axis tags

 

To add an axis, click the [+] toolbar button, and select a registered, unofficial, custom or global axis.

A global axis is used among several variable fonts of the same font family. The most common global axis is the Italic axis.

All axis have a minimum, default, and maximum value, except for global axes. These values are user scale coordinates, which are derived from axis mappings (see below) and master locations.

An italic font should not be include both Italic and Slant axes, unless the font family includes multiple italic designs with different amounts of slant. Most typefaces are made out of two variable fonts. One for the Roman and the other for the Italic styles. In such case both fonts should contain a global Italic axis, which is not used for interpolation.

Ordering

A value that applications can use to determine primary sorting of face names, or for ordering of labels when composing family or face names. Numbering starts with 0. To ensure consistency in how face names are presented to users, the axis ordering should be consistent across different fonts within a family, and with the style names of the instances.

Note: it seems not all software make use of this ordering, so it might be best to reorder the axes through the up and down arrow toolbar buttons.

Discrete (non-interpolatable)

This option is not something that ends up in a font, but it is used to determine whether an axis is part of interpolation or not. It can be used to design a font family as one variabel font, while on exporting it is divided into separate variable fonts, so all discrete axes become global.

Hidden (the axis should not be exposed directly in user interfaces)

Indicates a recommendation by the font developer that the axis not be exposed directly to end users in application user interfaces. Reasons for setting this flag might include that the axis is intended only for programmatic interaction, or is intended for font-internal use by the font developer. If this flag is set, the axis should not be exposed to users in application user interfaces except in specialized scenarios, such as a font inspection utility.

Mappings

Optionally provide axis mappings to modify aspects of how a design varies for different instances along a particular axis.

While designing a font, design coordinates are used, but they do not have to represent the actual user scale coordinates. For example, it is common to use the stem width as design values for Weight, but those need to be mapped to actual Weight values for the user. For example a variable font with only a Weight axis, can have a stem width for the Regular weight of 60 font units, while for the end user the actual Weight value will be 400.

A valid collection of map values is one that includes at least a mapping pair for the minimum, default, and maximum values. If default is equal to the minimum or maximum value, then that mapping has to be included twice. Otherwise the mapping is considered invalid and will be ignored. A mapping pair consists of two values, the first value in the user space, and the second value in the design space. For example:

100 16, 200 36, 300 56, 400 72, 500 108, 600 138, 700 170

 

The conceptual effect of these additional scale mappings is to make the variation along an axis less linear. Values change linearly within each segment, but additional segments make the way that values change across the entire axis range less linear overall. The effect might also be described as compressing some portions of the scale while making other portions less compressed.

Axis Values

An Axis Value provides details regarding a specific style-attribute value on some specific axis of design variation, or a combination of design-variation axis values, and the relationship of those values to labels used as elements in subfamily names. This information can be useful for presenting fonts in application user interfaces. It is also used by platforms to provide compatibility between rich typographic families with a wide range of styles and older applications that use legacy font family models.

These values are user scale coordinates. In a variable font, it is strongly recommended that axis values be included for every element of typographic subfamily names for all of the named instances.

Use the Generate from Instances toolbar option, to generate the axis values based on the Style Names and Axis Locations of all provided Instances.

 

Format

There are currently four different axis value formats.

1.Value, allows you to associate a specific axis value with a name (e.g. Bold -> 700 for the weight axis)

2.Range, allows a nominal value along with minimum and maximum value for a specific Name. Minimum value supports negative infinity by providing “-INF”, and maximum value supports positive infinity by providing “INF”.

3.Linked, allows you to associate a specific axis value with a name, along with a style-linked mapping from this value (e.g. Regular -> 400 & Linked -> 700 for the weight axis)

4.Multi-axis, allows two or more axis value combinations.

 

Elidable axis value name

If set, it indicates that the axis value represents the “normal” value for the axis and may be omitted when composing name strings.

Older sibling font attribute

If set, the axis value provides axis value information that is applicable to other fonts within the same font family. This is used if the other fonts were released earlier and did not include information about values for some axis. If newer versions of the other fonts include the information themselves and are present, then this axis value is ignored.

Elided Fallback Name

A name (such as “Regular”) that can be used when composing a name if all of the axis value names are elidable. For example, “Normal” weight and “Roman” slant may both be marked as elidable axis value names, and so a composed name for normal weight and Roman slant may result in an empty string.