How do I create a replacement font (font C) with the glyphs from font A but with the metrics from font B?
Also, I want all characters not present in font B not to be present in font C and I want to receive a warning for every character present in font B but not in font A, so that I can create a replacement that supports the exact same characters.
I think that fonttools
would be a good tool for this, but I am not very familiar with the way it works.
Comments
Since font B is not open source, you should check what its license permits or prohibits in terms of decompiling, and that will determine if or how you can go about getting the metrics to copy into the source for font C.
The actual process of copying the metrics of font B into the source for font C should be pretty easy in any of the common font development tools. And you will also be able to quickly compare character set coverage and identify the glyphs you need to add to font C to match the character set of font B.
FontForge remains the go-to open source font development tool, but I think that is more due to the failure of alternative projects to progress very far, rather than on any particular virtues of FontForge. Depending on what platform you are on, and if you are willing to use a proprietary font tool, I could make some recommendations.
I'm not sure where the license terms on this matters, because there are exceptions to various jurisdictions copyright regulations for decompilations. I seem to recall Brasil is especially strong on defending the public's rights around this. I also seem to recall something about USA font case law (to do with typewriters?) about 3rd party "fonts", when they were physical, where making replacement parts was ruled allowed under "right to repair" style doctrines.
I read that when Monotype Arial was introduced to Windows it was metrics compatible with the Linotype Helvetia in postscript and macOS, along with MT Times New Roman to LT Times, and Courier New to Courier. Possibly in The Adobe Story(?).
I believe there were also in the 90s/00s some "Office" versions of the most popular FontFont typefaces like FF Meta that were metric compatible with Arial.
Later in the 00s, Ascender Sans, Ascender Mono and Ascender Serif were developed by Ascender Corp and licensed to Red Hat as Liberation Sans, Mono and Serif under GPL+FE, and soon after to Google as Arimo, Cousine and Tinos; and these were updated by Monotype after acquiring Ascender Corp. Those are metric compatible with Arial, Courier New and Times New Roman, down to the hinting as I recall from a conversation with Tom Rickner at a TypeRight.org event in Seattle in 2008.
About a decade ago, a few designers made versions of a few OFL fonts like Lato that are metric compatible with Microsoft's C fonts like Calibri (this example is called Carlito), that ship in ChromeOS.
"We design stuff for Bahn and Bosche and the IT guys, everyone in there, takes [Arial] as a benchmark. Our stuff is way better, its more legible and prettier and all the rest of it, and they say 'Oh no, its gonna be exactly the size and the height and every single pixel has to be equivalent, even though its a crap typeface, because it is a benchmark."
-
So not FontFont versions, but custom brand type from MetaDesign, I guess?
You'd have to ask them how they did it, maybe they made a variable font that doesn't copy the values but can still offer them, like one clever TypeDrawers poster suggested the last time this topic came up
Making copies for the purpose of making replacement parts is a common exception to copyright restrictions.
https://www.wrays.com.au/insights/industry-insights/copying-replacement-parts/