Kerning Visually
Work on the pair's effective value while keeping its scope visible. A small adjustment can affect one combination or hundreds of class-member combinations. Check which glyphs or classes the current pair represents before changing it.
Kerning Mode
Open a Glyph window and press K, or choose the Kerning tool. Activating the tool without an existing Glyph window can open a new Kerning tab or window from the selection. With focus in the Font window, typing K can instead select the k glyph; use the tool control when you intend to change editing mode.
Kerning mode emphasizes the active pair. The class cloud above the text helps show related members while you judge the pair.
Turn on Apply kerning in the Glyph window when judging the corrections. The Metrics table shows widths, sidebearings, and the value between adjacent glyphs. Kerning mode can have its own background color, and the canvas suppresses some value labels at small display sizes. Zoom in or use the numeric field when a label is not visible.
Keep the Kerning and Pairs & Phrases panels nearby. The first shows stored pairs; the second supplies text to work through. Changing a text sample does not itself add a pair.
Editing Pairs
Click the second glyph of a visual pair, then drag it toward or away from the first. You can also drag the kerning thumb below the pair when spacing controls are shown, or enter a value numerically in the kerning field.
The kerning widget places the current pair value between the two side identities. The example’s value is −100.
A green spacing indicator represents negative kerning, yellow positive kerning, and white the unkerned state. Read the numeric value and pair scope as well as the color. The Kerning panel records the resulting pair.
Adjust by keyboard or precision drag
Left and Right adjust the current value using the ordinary metrics step, normally one unit. Shift uses the larger metrics step, normally ten units. These steps are configurable in Preferences > Distances. On macOS, Cmd+Left/Right provides a 100-unit adjustment. Do not use Control as a universal larger-step shortcut: in kerning it also determines exception scope.
The metrics/kerning drag lever in Spacing preferences makes pointer movement produce a fraction of the distance as a value change. Use it for fine adjustments; Shift-drag provides the direct movement behavior. For an exact large change on any platform, enter the number rather than combining unfamiliar modifiers.
The contextual widget's Kerning state also displays the pair members and its value. Confirm that it shows the intended pair before entering a number there.
Create an exception
When a glyph belongs to a kerning class, an ordinary adjustment uses the class relationship unless a more specific existing exception is active. Hold a modifier while making the first change to create a narrower pair:
| Modifier | Scope created |
|---|---|
| Control | Individual left glyph against the right class. |
| Alt | Left class against the individual right glyph. |
| Control+Alt | Individual glyphs on both sides. |
On macOS, Control here means the physical Control key, not Command. Once the exception exists, continue editing it without keeping the modifier held. Inspect the displayed pair names to confirm the scope.
For example, suppose L_T against R_A uses −80, but the Adieresis member needs −40 against every member of L_T. Display T Adieresis, hold Alt for the first drag adjustment, then release it and enter −40 for the new exception. Confirm that the pair reads L_T against Adieresis. The other R_A members keep the class value; −40 replaces −80 for the exceptional scope rather than being added to it.
Prefer the narrowest shared exception that expresses the actual problem. If one accented member needs a different value against the entire opposite class, a one-sided exception is clearer than many identical glyph-to-glyph exceptions.
The kerning classes cloud is a semi-transparent overlay of the class members behind each glyph of the pair. Toggle it with View > Metrics & Kerning > Kerning Classes. While an exception modifier is held, the cloud disappears on the affected left, right, or both sides, identifying the glyph-specific scope. Show All Combinations in the Kerning panel provides another comparison. Check more than the representative: an accent or terminal in another member can collide even when the displayed base pair looks correct.
With the canvas focused in Kerning mode, press W or | to swap the displayed pair order for comparison. That is a different pair and need not use the same value.
Remove versus set zero
Use the pair deletion control or delete the selected pair in the Kerning panel when you intend to remove its stored entry. Backspace can remove the current exception in Kerning mode. Deleting an exception reveals the next applicable broader pair, so the visible result may still have kerning.
Entering zero is not always the same as deleting. A zero-valued glyph exception can suppress a nonzero parent class pair. FontLab can retain that explicit zero for the override, while a zero class-to-class value or a pair with no broader source may be removed. Inspect the entry and its inherited behavior instead of assuming that a zero field means no stored exception exists.
Kerning Panel Operations
The pair list identifies each side and its value, including class indicators. Double-click a value to edit it. Selected rows can be adjusted together, so confirm the selection before using a batch command or keyboard step.
The Kerning panel combines pair filtering, saved values, and a preview of the selected pair in context.
Use Find pairs with patterns such as A *, * A, or A V to find left-side, right-side, or exact combinations by glyph name. The side selectors further restrict the list using the current font view or selection. Clear those filters before assuming that a missing row means the font has no corresponding pair.
Show All Combinations expands a class-based case for proofing. Context controls add neighboring letters to the preview so that a pair can be judged in a line rather than in isolation.
Adjust and reorganize pairs
Adjust Pairs… applies bulk changes to the selected scope. Remove Pairs… can remove entries by criteria such as thresholds, missing glyphs, or cross-script relationships. Read the criteria and target scope before applying; a cleanup threshold can remove deliberate small corrections or exceptions.
Remove Pairs separates thresholds, exception handling, and script criteria. Enable only the criteria you intend; the displayed values are an example, not recommended defaults.
Remove All Pairs... clears a broader kerning set than deleting selected rows. Its confirmation offers Also remove kerning classes and, in a multi-master font, Remove kerning in all masters. Save the source and inspect both choices before confirming; clearing all pairs is not a command limited to the current pair selection.
The class-conversion commands have different consequences:
- Compress to Class Kerning consolidates matching behavior conservatively, retaining differences rather than assigning the same value to every newly grouped combination.
- Flatten Class Kerning expands class relationships into individual pairs. The classes can remain defined even though the pair representation changes.
- Extend Class Kerning can make previously unkerned member combinations inherit class values. It changes coverage as well as representation.
Save the source before a broad conversion and compare effective values, not only pair counts. A representation round trip need not preserve the original names, order, or exact number of stored entries.
Audit Exceptions checks member combinations against the minimum-distance threshold in Preferences > Spacing. In the results dialog, choose Review to inspect the flagged combinations in a Kerning window and create exceptions yourself, or Add exceptions to create automatic corrections. Check their fit in text afterward: a distance threshold does not decide the preferred optical spacing of every pair.
Use autokerning as a draft
FontLab’s Preferences > Spacing > Autokerning > Autokerning method selects the automatic method. In Kerning mode, Semicolon invokes the configured normal route and Shift+Semicolon the alternative route on the corresponding keyboard mapping. The Kerning panel’s Generate command provides batch access. For a target distance, select pairs and use its Set Kerning… command to open Kern to distance. As with autospacing in Spacing Glyphs, review the scope and treat generated values as a starting point.
Kern to distance instead works toward a specified separation. This can help establish a consistent starting gap, but equal geometric distance is not necessarily equal optical spacing.
Neither algorithm replaces a proofing pass. Check representative letters, exceptions, punctuation, and the intended text sizes. Do not assume every invocation preserves existing values: an interactive autokern command can set the current pair's value directly.
The Superkerning Panel
Open Window > Panels > Superkerning to work through stored pairs and suggested pairs in one list. A suggested pair comes from the panel's text list; it is a proposed relationship to review, not a saved kerning value merely because it appears. Editing that row creates or updates its kerning data in the current master.
Use Find pairs to narrow the list by glyph names or class members. Click a column header to sort, and check the pair count alongside the active filter. In the panel menu, Suggested pairs… chooses the text list, and Show suggested pairs controls whether its unsaved proposals appear. This list is separate from Pairs & Phrases.
Suggested pairs follow the font's kerning classes where those classes exist. Read the left and right identities before editing: a class pair affects its member combinations, while a stored glyph-specific exception appears as its own relationship. To create a new exception, use the Kerning-mode modifier workflow above, then inspect that exception's stored row in Superkerning.
Data and preview views
Choose the view in the panel menu:
| View | What it shows |
|---|---|
| Table view | Pair data in Left, Value, and Right columns, without outline previews; class names identify shared sides. |
| Simple preview | Each pair centered in its string context, with its value. |
| Detailed preview | The contextual pair plus the semi-transparent class-member cloud, so other members can be compared. |
The preview-size control changes the displayed size in the visual views. Space provides a clean preview while the pair list has focus. Check the view after releasing it: a quick tap can leave the clean-preview state selected.
Pair review and adjustment
- Make the intended font and master current, then open Superkerning.
- Choose the suggested-pair list if needed and use Find pairs to isolate a manageable group.
- Select a row and inspect both side identities, its stored or suggested status, and the contextual preview.
- Double-click its Value cell for an exact entry. In a preview view, use Left/Right for small adjustments or drag the pair horizontally. Shift with Left/Right uses a larger step.
- Inspect the resulting value and class-member fit. Continue to the next pair, then check the adjusted text in the Glyph window.
Press ; with the list focused to autokern the selected pairs, or use the panel's autokerning control. Review those results as starting values. The edits support Undo; Escape cancels a preview drag before it is committed. General kerning commands in the panel menu can have font-wide scope, so their target is not necessarily the rows currently selected here. Use Kerning mode for running text, the Kerning panel for list and batch work, and Superkerning for reviewing many pairs together in context or as data.
Kerning across Masters
Each master carries its own kerning. Establish consistent class meaning, then adjust values for each design. Preview intermediate locations with the Variations panel so that corrections are judged between masters as well as at their endpoints.
Font > Kerning > Match Kerning restructures the master set around the main master's class system. Its workflow flattens class pairs, synchronizes classes, reconciles pair coverage, and compresses the result back into classes. Save before running it across a developed family and inspect the explanatory dialog.
A missing pair and an explicit zero are different source states. The interpolation system can treat missing corner values as zero while deriving missing intermediate values from surrounding sources. Check the resulting pair progression rather than filling every absent intermediate entry with zero indiscriminately.
Kerning interpolates between masters but does not support ranged intermediate masters. A ranged glyph correction therefore does not create a ranged kerning correction. Inspect the pair through the actual master range in the Variations preview.
Keep the source values and the interpolated result distinct. A value shown at an intermediate location is calculated from the participating kerning sources; it is not another stored pair merely because the preview displays it. Compare the same pair at the source locations and between them, including class members and exceptions. If the result needs correction, identify which source relationship should change before editing a master. Consistent coverage across the relevant sources is as important as the value in one visible pair.
Importing and Exporting Kerning
Use Copy Kerning From to bring in data from another open font or master. Review how classes and existing pairs will be handled before copying. Similar glyph names do not guarantee that the source values suit the destination shapes.
File > Import > Metrics and File > Export > Metrics provide metrics-file exchange. Import acts on the relevant master and can include spacing as well as kerning; select categories and review widths before treating it as a kerning-only transfer.
Opening an OpenType font can convert supported GPOS kerning into visual pairs and classes. More complex positioning may not fit that model: contextual rules, overlapping class systems in several subtables, multi-step adjustments, or richer value records need separate inspection.
Opening a font with kern decompilation to the Features panel enabled can place its kerning there as FEA. A kern definition imported or edited in that panel can be converted with Font > Kerning > Import from [kern] Feature for the current master. Keep the authored source, compile successfully, and compare the converted result. Decompilation is a useful editing route, not a guarantee that every positioning relationship becomes a simple editable pair.