🍿 Custom image sizes for Steam

Snacks (🍿) are my collection of recipes for solving problems. Often recorded (and cleaned up) from actual discussions where I'm involved in helping others with technical problems. Not all solutions are mine but I started collecting them in one place because you never know when you need one.

When you add a non-steam game to Steam, it doesn't have any graphics associated with it.
You can add custom ones through Steam's different pages. Here are the dimensions of those images and where to add them.

Example images from SteamGridDB.