Sorry if this is off-topic, but I had a little question regarding the bold fonts in Computer Modern. As far as I can tell, Knuth created two bold fonts: one called cmb, which is a little more condensed, and an extended bold font cmbx. However, everyone, including Knuth himself, seems to use only the extended bold font. Is there a historical/practical reason behind this? I couldn't find any mention of this online, but perhaps Knuth mentions his reasoning in Computers and Typesetting: Volume E? (I sadly don't own this book.)

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I actually quite like the ``condensed'' font and looking at many other fonts I see in mathematical papers and books (including Monotype Modern, which Computer Modern was based off), the bold variants are usually the same width as the default roman characters. By analogy, this would make cmb the go-to bold font for Computer Modern.

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I don't know, but I suspect that this is a lingering artifact of the first version of Computer Modern, called Almost Modern (am*). Metafont79 tended to make fonts darker because of its use of pens for all character drawing. There were both amb10 and ambx10 fonts in this system, but the amb10 fonts would be a bit clogged up and that led to the use of ambx10 in the TeX incunabula. When the cm fonts were finally produced, cmb10 was more usable, but use of cmbx10 kept layouts closer to the older style so it ended up being the preferred style.

Perhaps someone still has the old am* bitmaps and tfms around to be able to produce a sample output of how amb10 and ambx10 compare.

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    Wow, thanks for the cool info! I googled Almost Modern and it turns out I have a book (Combinatorics, by Béla Bollobás, 1988 reprint) that was typeset in Almost Modern (every instance of the letter `y' has the telltale notch). Alas, it seems like he always used the extended bold, so I cannot give an example of both bolds side by side. I'd love to see this, though, if anyone has the old bitmaps!
    – marcelgoh
    Jul 31, 2020 at 15:53
  • A bit of digging shows that Knuth only made one size of amb versus ambx5–10. There were also ambi10 and ambc10. I've only been able to locate tfms in my initial search. I suspect that the bitmaps may have been lost to the sands of time.
    – Don Hosek
    Jul 31, 2020 at 16:57
  • Thanks for trying to look for the bitmaps! I will ask some older professors I know; perhaps they have the files lying around somewhere. I will update this post if I find anything. Do you know of any examples in-print, perhaps? TUGboat articles pre-1982 would be typeset using the am* fonts, I imagine. There might be some examples of amb being used in the wild.
    – marcelgoh
    Jul 31, 2020 at 17:50
  • The am fonts were still in pretty widespresd use into 1986 or so. I think the first versions of PCTeX might have had am fonts? @BarbaraBeeton might have some ideas on where the bitmaps could be found.
    – Don Hosek
    Jul 31, 2020 at 18:01

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