Newsprint is absorbent, uncoated and slightly grey. Ink soaks into the fibres and spreads by a small amount in every direction, which printers call dot gain. Everything that goes wrong with type on newsprint traces back to that one property, and choosing a typeface with it in mind is most of the battle.
What ink spread does to letterforms
Spread thickens every stroke slightly. On a robust typeface that is barely noticeable. On a delicate one it closes the small gaps inside letters: the counters in an e or an a fill in, the joint where a serif meets a stem turns into a blob, and hairline strokes either thicken disproportionately or break up.
The typefaces that suffer most are the elegant high contrast serifs, the ones with a dramatic difference between thick and thin strokes. Bodoni and Didot are the obvious examples, and they are exactly what people reach for when they want a paper to look classic. They are magnificent at headline sizes and unusable at nine point on newsprint, because the thin strokes disappear while the thick ones spread.
What to use for body text
You want a serif with sturdy strokes, generous counters, low contrast between thick and thin, and a large x-height so the letterforms are as big as possible at a given point size. These qualities are exactly what the classic newspaper faces were designed for, because they were drawn for this paper and this press.
Georgia is the most available good answer and it is on every machine. It was designed for low resolution screens, which turns out to be a very similar problem to low resolution paper: big x-height, sturdy strokes, open counters. Charter, Chaparral and PT Serif are all sound. Among the true newspaper faces, anything in the Times family works because that is literally what it was cut for, though it sets narrow and can look cramped.
Avoid Garamond and its relatives for body text here. They are beautiful and they are drawn for fine printing on good paper, with small x-heights and delicate detail that newsprint simply cannot hold.
Size and spacing matter more than the typeface
Newspaper Club sets its floor at 8pt and adds that some fonts print well smaller, which is an honest way of saying it depends on the face. Treat 8pt as an absolute minimum rather than a target. Nine point is the standard newspaper body size and it is standard because it works.
Line spacing does more for readability on newsprint than any font choice. Ink spread reduces the apparent white space between lines, so type that looks adequately spaced on screen looks tight on paper. Setting leading at around 1.2 times the point size is a sensible default and going slightly looser rarely hurts.
Line length is the other half. Somewhere between forty-five and seventy-five characters a line is comfortable, and newspaper columns sit deliberately at the short end of that. If your columns are giving you ninety characters a line, add a column rather than reaching for a smaller font.
Headlines, where you can be bolder
At headline sizes ink spread stops mattering, because the strokes are thick enough that a fraction of a millimetre changes nothing. This is where the dramatic serifs belong. A Bodoni or a Playfair Display headline over a sturdy, plain body face is the classic newspaper pairing and it works precisely because each face is doing the job it can do.
Condensed faces earn their place in headlines too. Newspaper headlines have to say a lot in a fixed width, and a condensed grotesque fits more characters without dropping the point size. Just keep condensed type out of the body text, where it costs readability at exactly the size you cannot afford to.
Two things that are not about typefaces at all
First, set black text to 100 percent K only, never a mix of all four inks. A rich black built from cyan, magenta, yellow and black requires four plates to align perfectly, and on a newspaper press they do not. What you get is text with faint coloured fringes. This single setting causes more disappointing newspaper text than any font choice.
Second, be careful with reversed type, white text on a dark background. Ink spreads inward as well as outward, so the dark area closes in on the white letterforms and thin strokes vanish. If you reverse type, go up a size or two, choose a heavier weight, and avoid delicate serifs entirely.