Designing glyphs can be very complicated. The Font Validation wizard, available from the Font menu, identifies common potential problems and if possible points you to the specific item (e.g. glyphs, contours and coordinates). It validates all glyphs and optionally fixes detected problems.

 

The specific validation tests are explained here:

Duplicate components

This problem will be reported when validating composite glyphs with two or more identical glyph members.

Empty components

This problem will be reported when validating composite glyphs with empty glyph members.

Overlapping components

This problem will be reported when validating composite glyphs with intersecting glyph members. Some font designers consider overlapping composite components an error, while others don’t mind. We recommend to avoid overlapping contours.

Duplicate contours

This problem will be reported when validating simple glyphs with two or more identical contours.

Contours with one or two points

This problem will be reported when validating simple glyphs with contours with one or two points.

Contours with incorrect direction

This problem will be reported when validating simple glyphs with contours that have an incorrect direction (Contours that need to be filled black must have a clockwise direction. If we want to make a white area inside an existing contour we must make the direction of the new contour counterclockwise.).

 

Off-curve extreme coordinates

This test checks whether all off-curve points are inside the global bounding box (and optionally their local bounding box). You can customize this feature through the Options dialog.

The left image shows two red rectangles. The large one is the global bounding box and the smaller rectangle is a local bounding box between an on-off-on-curve sequence. Both off-curve points lie outside their bounding box. With local detection enabled, the right image shows the result of clicking the Add on-curve extremes button on the Validation panel.

Redundant points

This problem will be reported when validating simple glyphs with contours with redundant points.

Duplicate knots

This problem will be reported when validating simple glyphs with contours with two adjacent points that have the same coordinates but one is on-curve and the other is off-curve.

Intersecting coordinates

This problem will be reported when validating simple glyphs with (self-)intersecting contours. Avoid crossing contours whenever possible.

Note: Older PostScript Level 2 drivers do not support overlapping contours.

Suspicious points

This problem will be reported when validating simple glyphs with contours that have points that require attention because they are likely to be incorrectly positioned.

Interpolation issues

Detects these issues with variable fonts:

•Mixed up contours and/or glyph members

•Start points not matching

•Different contour directions

 

Unbalanced Components

This issue is detected when in a variable font a glyph uses components that have different scaling or rotating values. This is not an issue during the design, but as the OpenType format does not support it, such glyph outlines will be converted to simple outlines (contours) on export.

 

Note: The Validation features are not available in the Home Edition of FontCreator.