What’s the best way to install a tar.gz file?

A tar.gz file is basically a compressed archive, and it can contain a variety of files, including source code or binaries. First off, you might want to check what's actually inside the archive. Just because you converted it to a deb doesn't mean it has everything you need to run it. In this case, the link you shared shows that the tar.gz file contains the source code, which means you'll have to compile it yourself rather than just installing it directly.

You're looking at source code there, so you'll need to compile it instead of just installing it as you would with a standard application. Check the README for instructions on how to build it on Linux, which you can find here: https://github.com/PintaProject/Pinta?tab=readme-ov-file#building-on-linux. If that sounds like too much work, you might want to consider different installation methods.

Yeah, honestly, the easiest way is to grab it from Flathub or Snap Store. There's no need to deal with that tar.gz file for installation. Just check the Pinta GitHub page for quick install buttons for modern methods!

Seriously, why are you using such an old version? If you're after Pinta, it's also available as a flatpak. Just run a quick search in your terminal with `flatpak search Pinta`, and you'll find the newer versions easily installable, which saves you from any hassle involving source code.