[coconutrandom]

If anyone is interested in automating it, I wrote up quick howto in Python a few days ago. https://readevalprint.com/Schmelvetica.html

[app4soft]

Why fonts extension is .TTC?

    ORIGINAL_FONT_PATH = "path/to/Helvetica.ttc"
    GLORIOUS_FONT_PATH = "path/to/Schmelvetica.ttc"

[danaliv]

A TTC is a TrueType Collection. Multiple fonts in one file. Instead of having separate files for every size, weight, etc. they’re combined into one. The major advantage is the ability to share glyphs between fonts instead of duplicating information in each file.

[coconutrandom]

Ah yes, ".ttf" will work just the same.