I like the Computer Modern font when printed on paper.

On low DPI screens (e.g. 96 or even 144 DPI), Computer Modern feels too thin and spindly.

Recently, I came across the mlmodern (https://ctan.org/pkg/mlmodern?lang=en) font. It is a "heavier" version of Computer Modern and I use it for all my documents.

If you have a certain printer to use, you can tweak the Metafont mode for the fonts and create your preferred look. The definitions for various printers are in the file modes.mf

For example:

% From {\tt stsmith@ll.mit.edu}, 10 May 93.

% With |fillin=0|, the diagonal of {\tt cmtt10}'s `z' is too thin.

% |blacker=.8| too thin, 2 too thick.

mode_def docutech = %\[ Xerox 8790 or 4045 (600dpi)

mode_param (pixels_per_inch, 600);

  mode_param (blacker, 1);

  mode_param (fillin, .1);

  mode_param (o_correction, 0.9);

  mode_common_setup_;

enddef;

Using the rasterized fonts is very much an edge case these days. I'd also note that back when I used to manage this on University systems (in the days before dvips would automatically call mf to generate needed fonts), it was often the case that at lower resolutions (<600dpi), the CM code often ran into errors from the necessary mode_def parameters. Xerox printers were especially troublesome because they used a "write white" strategy for printing. A "write black" printer (e.g., the classic HP LaserJet), marked the page by using a laser to charge the parts of the page that should get toner. A "write white" printer charged the whole page, then used the laser to remove the charge from the parts of the page that should not get toner. On a "write black" printer, a pixel was a little bit bigger than its claimed size. On a "write white" printer", a pixel was a little bit smaller than its claimed size.

I was supporting Xerox 8700 laser printers at the time and the settings for a write white printer inevitably caused errors for many characters until I was generating at least a .600gf file. I have vague recollections of the same issue coming up occasionally even when I was printing to a 1200dpi Compaq.

Thanks for sharing! Those must be exciting times. I remember tweaking the fonts only once for printing my diploma thesis back in the 90s; but contrary to the most opinions, I made the fonts even lighter, because of the ultra white paper, we were obliged to print to. It was a very big file due to the 1200dpi rasterized fonts, but the result was better than any print shop could produce at that time.