Following these guidelines helps to communicate that you respect the time of the people managing and developing this open source project. In return, they should reciprocate that respect in addressing your issue or suggestion.
By contributing work to the Inter font project you agree to have all work contributed becoming the intellectual property of the Inter font project as described by [SIL Open Font License, Version 1.1](http://scripts.sil.org/OFL)
The Display (`opsz=32`) designs was derived from the text family ("Inter") and scaled to a different UPM (2048). It also had all of its kerning reduced.
This project uses "master styles" (or "key styles") which are combined using some clever math to generate other styles that are "mixed" from two masters. Because of this, there are some **very important rules** you must stick to:
- When adding or removing a glyph, you _must_ add or remove the same glyph in all master fonts. If you're using Glyphs.app, this is automatically taken care of, but not with RoboFont or some other font tools.
[Multiple Masters: Keeping Your Outlines Compatible](https://glyphsapp.com/tutorials/multiple-masters-part-2-keeping-your-outlines-compatible) is a great article on this topic.
When making changes to the typeface and its source files, it's a good idea to sample your changes not only in a font editor or graphics editor, but also in real-world scenarios.
All resulting font files are written to the `build` directory with `Inter-` as the filename prefix. The `Makefile` file contains information about more possibilities of `make`.
[**The interactive Lab**](#interactive-lab) is a great tool for quickly exploring your font files. It's a web-based tool which you start in a terminal by running:
This project comes with a simple web-based application for debugging and previewing the font. It's a very useful tool to have when working on the font.
You can now visit the URL printed on the screen to use the lab. Simply `make -j web` for all styles or `make var_web` for quickly building only the variable font. Then reload the web page to try the new build.
Kerning is the concept of harmony in the pace of characters, defined as a set of distances between specific character pairs, like "A" & "c". Good kerning makes words more readable. Oftentimes this means that when adjusting kerning, you have to look at whole words and sentences when adjusting the kerning of a pair, since the spacing between two characters should work in harmony with the spacing of all other characters.
All major font editors provide user interfaces for previewing and adjusting kerning. There is even dedicated software specifically for working with kerning.
- If you're using Glyphs, read more about kerning and how the "padlock" icon affects kerning specific pairs vs groups here: <https://glyphsapp.com/tutorials/kerning>
- If you're editing the UFO files, the groups can be found in the `groups.plist` files.
If a glyphname is missing in kerning groups, define a new group for it. Group name should reflect the most prominent or common glyph that belongs to the group. For example, "V" for a group containing "Y", "Ÿ", "V" and "W". A kerning group is specific to one "side" of a glyph (left or right) and therefore the name should reflect a glyph which side is the most relevant one. For instance, consider the character "D" which on the left side looks like "M" and "L" but on the right side looks like "O" and "C". It belongs to the "O left" group and the "M right" group. Similarly for "g" ("o left", "m right"), "p" ("m left", "o right") and many other glyphs.
There are several tools included with Inter to help "wrangle" metrics, generate glyphs, create PDFs and so on. You can find these tools in the `misc/tools` directory. They are all command-line tools and their usage can be queried by providing the help flag `-h`.
