fvar

com.google.fonts/check/varfont/bold_wght_coord

The variable font ‘wght’ (Weight) axis coordinate must be 700 on the ‘Bold’ instance.

Rationale:

The Open-Type spec’s registered design-variation tag ‘wght’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght does not specify a required value for the ‘Bold’ instance of a variable font.

But Dave Crossland suggested that we should enforce a required value of 700 in this case.

com.google.fonts/check/varfont/regular_ital_coord

The variable font ‘ital’ (Italic) axis coordinate must be zero on the ‘Regular’ instance.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘ital’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_ital

If a variable font has a ‘ital’ (Italic) axis, then the coordinate of its ‘Regular’ instance is required to be zero.

com.google.fonts/check/varfont/regular_opsz_coord

The variable font ‘opsz’ (Optical Size) axis coordinate should be between 9 and 13 on the ‘Regular’ instance.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘opsz’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_opsz

If a variable font has a ‘opsz’ (Optical Size) axis, then the coordinate of its ‘Regular’ instance is recommended to be a value in the range 9 to 13.

com.google.fonts/check/varfont/regular_slnt_coord

The variable font ‘slnt’ (Slant) axis coordinate must be zero on the ‘Regular’ instance.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘slnt’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_slnt

If a variable font has a ‘slnt’ (Slant) axis, then the coordinate of its ‘Regular’ instance is required to be zero.

com.google.fonts/check/varfont/regular_wdth_coord

The variable font ‘wdth’ (Width) axis coordinate must be 100 on the ‘Regular’ instance.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘wdth’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wdth

If a variable font has a ‘wdth’ (Width) axis, then the coordinate of its ‘Regular’ instance is required to be 100.

com.google.fonts/check/varfont/regular_wght_coord

The variable font ‘wght’ (Weight) axis coordinate must be 400 on the ‘Regular’ instance.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘wght’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght

If a variable font has a ‘wght’ (Weight) axis, then the coordinate of its ‘Regular’ instance is required to be 400.

com.google.fonts/check/varfont/slnt_range

The variable font ‘slnt’ (Slant) axis coordinate specifies positive values in its range?

Rationale:

The OpenType spec says at https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxistag_slnt that:

[…] the scale for the Slant axis is interpreted as the angle of slant in counter-clockwise degrees from upright. This means that a typical, right-leaning oblique design will have a negative slant value. This matches the scale used for the italicAngle field in the post table.

com.google.fonts/check/varfont/wdth_valid_range

The variable font ‘wdth’ (Weight) axis coordinate must be within spec range of 1 to 1000 on all instances.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘wdth’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wdth

On the ‘wdth’ (Width) axis, the valid coordinate range is 1-1000

com.google.fonts/check/varfont/wght_valid_range

The variable font ‘wght’ (Weight) axis coordinate must be within spec range of 1 to 1000 on all instances.

Rationale:

According to the Open-Type spec’s registered design-variation tag ‘wght’ available at https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght

On the ‘wght’ (Weight) axis, the valid coordinate range is 1-1000.