Carlos E. R. composed on 2015-11-13 02:24 (UTC+0100):
$ fc-match sans
cer@Minas-Anor:~> fc-match sans DejaVuSans.ttf: "DejaVu Sans" "Book" cer@Minas-Anor:~>
Yes, that's what I have just set a minute ago. The word "book" I don't know what it means above.
It's the name used for default or plain, not special, no slant, standard weight.
to find out which font it is. I can't tell from that image what bothers you. Those fonts are all much too small here. Has it always been like that, or just changed after updating?
Always since install, which is a week old Leap 42.1. It looks different and more difficult to read than 13.1 in this same laptop. I can change the font in the header panel, but not in the body panel. It remains small and... I don't know how to explain, fuzzy.
In Thunderbird I set the size to "20", and it doesn't change anything. Ah, got something: in "advanced", I change the size of "mono" to "16", and it does change to bigger font, but they are very thin.
Apparently the AA settings in your new Leap installation are different from what you are used to. Those affect some fonts more or less than others, and the differences vary according to size as well. Perusing the following may make font differences easier to understand, especially if used in conjuction with changes to your AA settings:
http://fm.no-ip.com/Auth/Font/fonts-comps-ui15.html http://fm.no-ip.com/Auth/Font/fontm-droidmono.html http://fm.no-ip.com/Auth/Font/font-droidsans.html http://fm.no-ip.com/Auth/Font/fonts-comps-dejavu.html http://fm.no-ip.com/Auth/Font/fonts-comps-droid.html http://fm.no-ip.com/Auth/Font/
Well, after many tries I got it to something easier to read. Droid Sans Mono 15. It gets changed in the compose window, but not in the body panel.
If you mean by body panel the message content pane, it's probably using a different charset than your default. In about:config you'll find there are separate font family and size settings for a lot of different charsets, but only one is affected by the changes you made in "advanced". Before messing with them you may need to tweak on the charset settings in the prefs UI.