Updated: February 7, 2018
If you're using the Plasma desktop, well you should because it's dope, and you happen to be using LibreOffice, which you most likely are, after all, let's face it, 'tis the most popular office suite for Linux, then you may have come across an annoying bug. Everything looks peachy but the LibreOffice interface has that grainy 2006 feel.
In this short guide, I will show you how you can improve the look & feel of LibreOffice so that it fits more naturally into the Plasma desktop environment. Moreover, the tweak also applies to a wider range of programs, and it should give you ever so slightly better fonts. Having read my Fedora font saga, you know what I'm talking about. After me.
You start LibreOffice, this is what it looks like. Notice the start difference between the title font and the file menu font. The latter is just too thin, looks weird, and it feels as though plucked from a completely different desktop.
There are several things you can try. One, OpenGL settings. This can potentially help how LibreOffice displays on the screen. LibreOffice > Tools > Options > View. Then you can toggle OpenGL on.
Do note that this setting may cause LibreOffice not to be able to start at all. This is a side issue, but you should be aware of the potential issue. If LibreOffice refuses to start thereafter, you should delete your program configuration and start fresh. The exact location of the configuration in the Plasma desktop is:
You can also test if enabling/disabling hardware acceleration makes a difference, as well as the use of anti-aliasing (aha, hint). You should close the program and start it again to see what gives. Lastly, for those among you who remember font tweaks, specific font changes for the interface are no longer possible as a user setting anymore.
What you do want to do on a more permanent basis is to change the anti-aliasing settings in the system fonts menu. By default, Plasma will use system settings, whatever they mean for your particular platform, graphics card and Plasma version. You want to override those. System settings > Fonts. Under anti-aliasing, change from system default to Enabled. Then click Configure to fine-tune your selection. Choose RGB for sub-pixel rendering type and slight for Hinting style. Restart LibreOffice.
You will notice that the menu now shows beautifully in font style and size that match the rest of the system, and it looks modern and elegant. You will also notice that the actual font on the screen looks a tad better. Compare please the before and after screenshots. Click to enlarge to full size, as the details are too subtle to see on resized images. You should ignore the actual icon theme, as it is not relevant - it does impact the overall look and feel, though. Just focus on the text part.
Fonts, the final frontier. These are the voyages of the OSS Linuxer. Its continuing mission: to explore strange new fonts, to seek out new kerning and new configurations, to boldly git where no one has forked before. In a nutshell, the font game remains the wild west of the distro world, along half a dozen other non-standardized, unregulated, unspecified yet critical aspects of desktop computing.
Perhaps this will go pro one day - see the pun there - but until that happens, we will need to invest time and energy fighting and figuring out fonts and other tweaks to make applications look and behave the part. LibreOffice is a high-profile victim in this game, and probably because it isn't an integral part of the KDE suite, it suffers double. Luckily, this little OCD tutorial will help you enjoy ever so slightly sharper fonts, from this day till the end of the world, we few, we happy few, we band of geeks. Engage.