Just managed to get compton working with a compton.conf file by placing it in ~/.config/compton.conf

The rules I setup are almost exact the same as the full config file list here:

https://ubuntu-mate.community/t/better-compton-compositing-better-than-other-choices-too/6260/6

I only changed the shadows to disabled.

There are a couple of modifications I would like to make but not sure were to start:

1) Opacity is changing automatically now based on which window is active or inactive and I would like to disable that 2) I would like to be able to exclude certain applications from general opacity settings and set a custom opacity setting for that one application 3) Be able to modify opacity level of the active window with a keyboard shortcut hotkey like I could in compiz.

Tried googling the application exclusions and they gave some complex answers about window type that I could not get working when I tried adding them to my config.

Edit: OS is Mint 19.1 MATE.