Type Lab starts with the real outlines of Inter. Weight and optical size use its original variable-font axes. Inter has no width axis: Type Lab calculates its own width changes from the relationship between corresponding nodes in Inter’s Thin and Black designs.
Width changes preserve stroke weight using corresponding nodes in Inter’s Thin and Black masters. Diagonal joins move together, and heavier weights receive a continuous readability adjustment. Spacing follows the reshaped letters. Width is a requested design value, not an exact percentage of every glyph’s advance.
Outer and inner radii work independently, including bowl-to-stem corners. Squareness follows curved bowls and inner shoulders. Aperture retracts open terminals without changing the advance width. Contrast changes horizontal stroke weight; joint thickness and upper/lower join angles change local connections. Height controls compensate horizontal strokes, and crossbars move with their attachments.
Use Text to test words, Glyphs to select one or more characters, and Edit glyph for a close view. All parameter cards appear in one grid: two columns on wide screens and one on narrower screens. Each has a live specimen that you can click to inspect on the canvas. The theme button switches the whole interface between white and dark. Each visit starts in Whole font mode. Returning to Text or Glyphs also returns to whole-font editing. Choose Edit selected or double-click a glyph for individual changes. Previous and Next follow the current single-glyph edit target. Individual edits inherit the other family settings. Restore selected to font settings removes those overrides.
Alternates include Inter’s native forms and new Inter-derived a, g and R constructions. Click a card to use that form in your preview and exported font. Some controls only affect matching geometry; alternate constructions remain experimental.
Adjust each glyph’s left and right spacing with the grips in Edit glyph. In Text, place the cursor between letters and press Command/Ctrl + Left or Right to adjust that pair. Hold Shift for ten-unit steps. Spacing and kerning are saved with your design, support undo, and are included in exported weights and families.
Name your family, export the .OTF, and install it through your operating system’s font manager. Your current settings are baked into the exported static font. Presets, including individual character edits, are saved in this browser.
Roboto Flex and Inter-based exports remain under the SIL Open Font License 1.1. You can use them in commercial brand work. Redistributed font files must retain that license and copyright notice; the font software cannot be sold by itself. The export embeds these notices.
This is a font-design prototype. Exports contain the supported outlines, your glyph spacing and explicit kerning pairs. The base fonts’ automatic kerning, mark-positioning and complete OpenType substitution tables are not retained. Review spacing, language support and extreme combinations before using a generated font in production.
Roboto Flex remains available for comparison, using its native width axis and Condensed balance adjustment. Antique retains the previous parametric and serif controls. Each base keeps separate saved presets.
Roboto Flex 3.000 and Inter Variable 4.001 by their respective project authors. The interface uses Geist, charcoal, warm white and green from Tremendo V2. Fontkit reads and interpolates its outlines. PathKit cleans modified contours. The OpenType writer and the legacy parametric engine are adapted from Prototypo, by Yannick Mathey, Louis-Rémi Babé and contributors, revision e82ac12a047a38d0a61e6ce979d7b3436e1f86a6.
This is an independent experiment. The upstream JavaScript notices, including MPL 2.0 and the package’s AGPL metadata, are preserved with the source. Original Prototypo styling and brand assets are not included.