# Which font expansion parameters are ideal for different fonts?

Following up on this question Set font expansion so that distortion is not noticeable I think a list of fonts and their respective ideal `stretch` and `shrink` parameters is missing. This would be a great addition to the LaTeX Font Catalogue but it's also a lot of work to do for all fonts and probably very subjective, too. So it needs to be collected somewhere. Why not start here? :)

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Yes, I am sure that it depends on the font how much it can be stretched and shrinked in relation to each other and in relation to other fonts. You may shrink Palatino more and stretch it less, while Minion and maybe Times can be stretched more but should not be shrunken that much.In the next step it depends on the viewer, so you cannot compare the opinion of two different people, judging two different fonts. There is one problem with expansion in standard LaTeX. It shrinks much more often than it expands. The last line of a paragraph is set normal while the lines above are shrunken. –  user18557 Dec 5 '12 at 16:14
Let's use promille (1/1000) as a unit, as microtype does, not percent (1/100) like Bringhurst did, because percent is too rough. –  user18557 Dec 5 '12 at 16:34
@user18557 Indeed, it would be nice if the pdftex hz algorithm integrated some badness calculation for expansion, too. This would not only affect the desired expansion of adjacent lines, but could also mitigate the greediness of expansion (pdftex always trying to shrink or stretch as much as possible). The reason why it was not implemented is that Thanh assumed that expansion limits should be specified strictly enough so that distortion is never visible. –  Robert Dec 5 '12 at 18:13
@user18557 But the problem that the very last line of a paragraph is never expanded is actually inherited from tex itself, which similarly does not adjust the last line's interword spacing according to the previous line. etex fixes this with the (fairly fameless) parameter `\lastlinefit`. Unfortunately, there is a long-standing bug with `\lastlinefit` and expansion in pdftex, where a positive `\lastlinefit` always leads to maximum expansion of the last line, which precludes the use of this otherwise useful command. –  Robert Dec 5 '12 at 18:14
@Christian Yes (when used together with expansion; otherwise it's of course fine). –  Robert Dec 5 '12 at 23:54

## 1 Answer

Based on this answer and calling on Bringhurst, the default values of `microtype` (±20‰) are quite fine for Minion Pro.

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I agree with Bringhurst in general but not in LaTeX. If you allow +- 20 promille, LaTeX tries to fill justified lines as much as possible by shrinking and sets the last line of the paragraph unexpanded. You can see the difference. A MWE is any justified text with expansion +-200 promille when the last line does not fill the whole line. So in LaTeX I prefer to allow less shrinking and more stretching so that the text averages at the natural width of the font. –  user18557 Dec 5 '12 at 16:38