Spacing Glyphs
Work in Metrics mode with Apply Kerning off and Simulate horizontal tracking at zero. Establish a repeatable text context, change one spacing decision, then compare the result in several strings. A useful default bearing should work beyond the one pair currently on screen.
Spacing Principles and Test Strings
Begin with reference glyphs whose spacing you can judge consistently. For uppercase work, compare a candidate among straight-sided H glyphs and rounded O glyphs. For lowercase work, n and o provide comparable references. Strings such as HHHHOHHHH, nnnonnoo, and alternating forms expose different relationships.
Use the Text Bar to type a control string. A glyphtext repeater can follow the glyph you are editing: n\@n\@o\@o keeps fixed neighbors while the repeater positions show the current glyph. Use the Pairs & Phrases panel's text samples to broaden the context after the initial comparison.
Look for consistent perceived white, rather than equal measured gaps at every point. The counter gives a useful internal reference for the amount of space a form appears to need beside it. Round forms often need tighter bounding-box bearings than straight forms because their edges recede. Treat that as a starting observation, not a fixed numerical ratio.
Compare the left and right sides independently. A glyph with asymmetrical geometry need not have equal bearings, and a symmetrical outline can sit in a context that calls for an optical adjustment. Test repeated letters, mixed straight and round neighbors, words, and punctuation before accepting the result.
If one pair remains awkward, first check that the candidate's bearings work with other neighbors. Pair-specific correction comes after the general spacing has settled; do not distort a useful default to solve one exceptional pair.
Editing Glyph Metrics
Make the intended glyph current and inspect its LSB, RSB, and advance width before changing them. These values are related: moving the drawing, changing one bearing, and changing the width are different edits.
Drag on the canvas
Drag a sidebearing line or its spacing triangle to change that bearing. The text reflows to show the result. Controls can act on a glyph occurrence in the string, but the edited value belongs to the glyph, so its other occurrences update too.
To reposition the drawing within an unchanged advance, enable Preferences > Spacing > Editing metrics > Drag glyph within advance width (off by default), then drag the glyph image. Moving it right increases LSB and decreases RSB by the same amount. Hold Option/Alt during the glyph-image drag to change its advance-width behavior instead. If image dragging does nothing, check that preference; boundary-line dragging remains available.
For fine movement, adjust Metrics and kerning editing changes value by 1/n of dragging distance under Preferences > Distances. A larger divisor gives a smaller metric change for the same pointer travel. Shift can restore the direct dragging response. This lever changes interaction sensitivity, not the output font's coordinate precision.
Use the keyboard
With the canvas in Metrics mode, the following combinations adjust the current glyph. Control means the physical Control key on both platforms, including macOS.
| Gesture | Result |
|---|---|
| Control+Left / Right | Decrease / increase LSB |
| Option/Alt+Left / Right | Decrease / increase RSB |
| Control+Option/Alt+Left / Right | Shift the drawing left / right within a fixed advance |
| Control+Option/Alt+Down / Up | Decrease / increase both bearings, changing the advance |
| − / + | Decrease / increase both bearings |
The base step and larger Shift step are configurable. Their usual values are one and ten units. With both bearings increased by one, the advance increases by two; do not confuse a one-unit bearing step with a one-unit width step.
On macOS, Command provides the larger 100-unit adjustment in the relevant metric-key combinations; Shift+Command requests a one-unit step. System shortcuts can intercept Control-arrow combinations. Use the fields or canvas controls if the operating system handles the key instead.
Three alignment keys move the drawing while preserving its advance width:
- { sets LSB to zero.
- } sets RSB to zero.
- | centers the drawing between the boundaries.
These are Metrics-mode editing shortcuts. Check keyboard layout and focus before using punctuation keys as commands.
Enter a value
Enter the required LSB, RSB, or width in the Metrics Table, the Metrics property bar, or the Metrics panel, then press Return/Enter. The Glyph panel and Glyph-state Contextual widget provide additional value-entry surfaces.
The Metrics panel places advance width and both sidebearings in a table, with the selected glyph shown below.
Check which glyph or selected rows the surface targets. The current-glyph bar is not a substitute for explicitly selecting a batch in a font-wide panel. After entry, inspect all three values so you understand which other metric adjusted.
The fields can hold expressions as well as numbers; see Relational Spacing. If a field is linked, a drag or keyboard change can add an offset to its expression instead of removing the relationship. Read the field after an edit rather than assuming it now contains a plain number.
For reuse within Metrics mode, Copy captures metrics from the current glyph; Paste onto another glyph applies the sidebearings, including expressions, rather than treating the copied advance width as a compulsory replacement. Check the target's resulting width after pasting.
Outline precision, computed expressions, and displayed numeric precision are distinct. Do not infer an internally exact integer result solely from an integer-looking field; inspect the intended output when sub-unit arithmetic matters.
Set widths or sidebearings for a selection
For a repeated metric change, select the glyphs in the Font window and open Tools > Actions. Check both the glyph and master scope before running the operation.
Set width supplies a target advance width. Choose Adjust both, Adjust right, or Adjust left to determine how that change is distributed around the drawing.
Set sidebearings offers separate left and right operations: Set equal to, Auto + adjust, Increase by, Decrease by, or Do nothing. Check the slanted-sidebearing and metric-line options as well. Leaving one side unchanged is different from setting it to zero.
Autospacing
Autospacing proposes sidebearings from a selected method. Use it to establish a starting fit, then judge the result in the same control strings used for manual spacing. Better general spacing reduces the pair-specific patching needed later; autospacing does not replace that judgment.
Choose Preferences > Spacing > Autospacing > Autospacing method:
| Method | Starting behavior |
|---|---|
| Optical | Analyzes the shape to estimate suitable bearings |
| Neural | Uses a learned spacing model where supported |
| Tight | Sets both bearings to zero around the relevant bounds |
| Custom | Sets both bearings to the chosen percentage of UPM |
For Custom, enter Autospacing value. At 1000 UPM, 5% gives 50 units on each side. Tight and Custom are geometric presets, not optical assessments.
Neural autospacing is primarily intended for the basic Latin uppercase and lowercase alphabet. Do not assume it supplies a learned result for every character or script. If a glyph receives no useful result, use Optical or set its bearings manually. Support depends on the available spacing model.
Link to key glyphs can let autospacing create metrics relationships to suitable reference glyphs. Inspect the resulting fields for links when you want independent numeric bearings.
Autospacing changes font metrics and can replace earlier spacing or relationships according to the selected method. Confirm the current glyph or Font-window selection before applying it.
In Metrics mode, press ; to autospace the current glyph. For a Font-window selection, choose Font > Metrics > Auto Space.
Check repeated letters, contrasting neighbors, and words afterward. A method can provide a useful first pass without resolving every optical decision.
Measurement Modes
The ordinary reference is the glyph's bounding box. Use it as the primary spacing basis when establishing exported default fit.
View > Metrics Line enables a movable horizontal measurement reference. Drag it to a useful height, such as through the lowercase body, to compare side clearances at that cross-section instead of at the drawing's overall extrema. Its distinct color and metrics-field indication help identify that mode.
This is not merely an additional passive label. With the Metrics Line active, displayed LSB and RSB describe intersections at its height, and edits can be interpreted on that basis. Values can therefore change when you switch measurement modes even though the outline and advance initially remain unchanged.
Metrics expressions use bounding-box values regardless of the Metrics Line state. An expression result and a line-based readout can differ for that reason.
The output font has no equivalent movable Metrics Line. Use it to investigate a particular clearance, then return to bounding-box measurement and inspect the actual fit. For italic work, also check which italic metric view is active so that you do not compare differently defined measurements as though they were the same value.