FYI this subject repeatedly comes up in Igor Ljubuncic's reviews of KDE Plasma. For example: http://www.ocsmag.com/2018/01/27/plasma-5-12-long-term-sweetness/

Fonts
This is a big one. I’ve talked about fonts time and time again, and I dread to even think about linking to all my different articles on this topic. In essence though, fonts are the Wild West of Linux, with distro and desktop developers sacrificing usability for aesthetics. Non-black fonts are harder to see, the fonts are often too small, and there’s a sub-optimal use of anti-aliasing settings, leading to severe eye strain almost across the board. Ubuntu leads in this regard, which makes KDE flavors that use Ubuntu as a baseline feel oddly out of place with their own setup.

If we implemented my recommendation, he would heap praise on us in his next Kubuntu review.

I really hate the Ubuntu font, but I guess it's not about my likes and dislikes!

What about Lato font? http://www.latofonts.com/lato-free-fonts/

I am using that in Plasma from > 1 year and for me it looks much better then default.

@kpiwowarski That is good too. I think it makes sense for Kubnutu to use the same font as its parent distro, but I might be interested in a discussion about changing the default KDE font size and face a bit. Noto Sans 10 always feels too small and light, and is a bit hard to read if you don't have perfect eyesight.

I followed the discussion in KDE which led to the adoption of Noto, and it was based mostly on their coverage of the world, in particular Asian font families, and right-to-left fonts often used in west Asia and some places in Africa. This really is a huge advantage around the world.

I don't like grayed-out fonts either, because my eyes aren't as sharp as they used to be!

I just changed from noto to ubuntu in my Konversation, and it is indeed easier on the eye. I didn't like Lato as much.

I have to imagine that Ubuntu has similarly good coverage, no? It really is a world-class font.

As far as I know, it does not. Look at the choices you are offered if you want Noto, in contrast to what you are offered if you choose Ubuntu.

Clicked send too quickly. I would support this if our international users were behind it. If not, I'd rather stick with Noto.

How does regular old Ubuntu handle the international character issue with their default font?

Even if we can't change the font to Ubuntu, I would advocate changing the default pt size from 10 to 11, and the window title from 10 to 12. It becomes a usability issue for people without perfect eyesight.

FWIW, from https://design.ubuntu.com/font/

The scope of the Ubuntu Font Family includes all the languages used by the various Ubuntu users around the world in tune with Ubuntu's philosophy which states that every user should be able to use their software in the language of their choice.
[...]
Coverage

1,200 glyphs, 200-250 languages (native languages of 3 billion people!).

You know what though, Noto Sans 11 is fine. It's a huge improvement over 10. We don't have to do Ubuntu.