Make your variable fonts better with FontLab 7
This 19-minute presentation by Adam Twardoch, delivered at ATypI Tech Talks 2021, goes beyond building variable fonts to the harder question: making them good. It covers quality assurance, interpolation checking, and the tools in FontLab 7 and related applications that help catch problems before a variable font ships.
Variable fonts are technically complex: a single font file encodes a continuous design space, and problems can appear at any point within it — not just at the named instances you tested. Twardoch demonstrates a systematic workflow for checking variable fonts across their full range, using FontLab 7’s variation preview alongside external tools to catch interpolation errors, contour incompatibilities, and metric inconsistencies.
The presentation covers how to set up masters for clean interpolation, what FontLab’s compatibility checker looks for, and how to interpret the results. Twardoch also discusses common failure modes — nodes that drift, contours that flip, anchors that interpolate incorrectly — and shows practical fixes for each.
Because this was a conference talk, the pace is faster and assumes more prior knowledge than an introductory tutorial. It is aimed at designers who have already built a variable font and want to raise the quality of their output, or who have run into problems they couldn’t diagnose.
Watch on FontLab TV.