Comment by ano-ther
25 days ago
Interesting that for a paper by Don Knuth himself the PDF was created with dvips (TeX Live) but then switched to Acrobat Distiller, resulting in a rather low resolution (at least on my screen).
From the document properties: > Creator: dvips(k) 2023.1 (TeX Live 2023) > PDF Producer: Acrobat Distiller 25.0 (Macintosh)
The issue is not of low resolution exactly, but font format.
Knuth uses bitmap fonts, rather than vector fonts like everyone else. This is because his entire motivation for creating TeX and METAFONT was to not be reliant on the font technology of others, but to have full control over every dot on the page. METAFONT generates raster (bitmap) fonts. The [.tex] --TeX--> [.dvi] --dvips--> [.ps] --Distiller--> [.pdf] pipeline uses these fonts on the page. They look bad on screen because they're not accompanied by hinting for screens' low resolution (this could in principle be fixed!), but if you print them on paper (at typical resolution like 300/600 dpi, or higher of typesetters) they'll look fine.
Everyone else uses TrueType/OpenType (or Type 3: in any case, vector) fonts that only describe the shape and leave the rasterization up to the renderer (but with hinting for low resolutions like screens), which looks better on screen (and perfectly fine on paper too, but technically one doesn't have control over all the details of rasterization).