Bringhurst Kerning Highlighter

Recreates the kerning test page from Bringhurst’s The Elements of Typographic Style (4th ed.) as a proofing specimen with kern-lapse pairs highlighted.

Installation

1. Download the zip file and unzip it.

2. Run the script in one of two ways:

   a) Run directly — Open the Script Editor panel (Window > Scripting > Script Editor), paste the contents of bringhurst-kerning-highlighter.js into the editor, and press Run.

   b) Save to Script Library first — Follow step (a) above, then click Save As… to save the script to the Script Library. Open the Script Library panel (Window > Scripting > Script Library) and click the saved script once to run it.

Purpose

Builds a dedicated proofing page from Bringhurst’s classic kerning test text so an unfamiliar font can be judged before its kerning table is tuned. The script places a text frame on the current spread, sets the test passage in the chosen font, highlights each kern-lapse pair, and italicises the runs that are italic in the source. It changes nothing in the existing document text — it only adds the specimen frame.

Use it as the first proofing step before previewing or applying kerning-pair changes.

This is only a specimen, not a diagnosis. The highlighted pairs are candidate kern-lapse positions — a well-kerned font may show correct spacing on them, and that clean result is itself the verdict. The typesetter’s eye, not the highlight, decides whether a font needs kerning applied.

How it works

The embedded test passage includes Bringhurst’s “Ask Jeff” lines, the of series, place names, and the closing date-and-time line.

1. The dialog collects the font, size, and highlight colour.
2. A text frame is created on the first spread, inset 10 mm on every side. Page and frame sizes are logged to the Console in mm.
3. The passage is set through StoryBuilder and placed with AddChildNodesCommandBuilder.
4. The italic source run is applied.
5. Each entry in the kerning-pair table highlights a two-character range with the selected highlight fill. The result and applied font/size are logged to the Console.

Dialog

• Family — font picker, required. The run aborts with an alert if no family is chosen.
• Size — point-size picker, range 4–144 pt, default 10 pt.
• Highlight Colour — colour picker, default mid grey (RGBA 200, 200, 200). One colour is used for every highlighted pair.

Cancelling the dialog aborts cleanly and logs cancelled to the Console.

Usage tips

• Proof at the size you will actually set, and re-run the specimen on every change of font size: the same pair can look fine at 10 pt and fail at display sizes, so each size needs its own verdict.
• Re-run the specimen in a different family to compare two candidate fonts side by side on identical text.
• Check the Console for the applied font, size, frame measurements, and cancellation status.

Requirements

• Affinity by Canva 3.3.
• An open document — the script alerts and stops if none is open.
• The proofing font installed and selectable in the font picker.

Known limitations

• Highlight positions are fixed story indices into the embedded test text. Editing the test text without updating the table misplaces the highlights.
• The frame always goes on the first spread; there is no spread picker.
• One highlight colour is used for all pairs — problem classes are not colour-coded.
• Frame creation, italic formatting, and highlighting run as separate commands, so reverting takes more than one undo step.

Changelog

1.1.0 - Renamed from kerning-highlighter.js (no behavior change)

1.0.1 - Maintenance release (script header, 19/09/2026)

1.0.0 - Initial version