This is a template for use in Paint.net (or any other program that can properly open .pdn files), that contains outlines for all the UI and text elements, so that you can create more elaborate backgrounds without having to guess where they are so that they don't interfere with any text.
To work, they must be put into a folder, and then put into the Assets folder in mods/Menu Backgrounds. If you have that mod installed you know how to do it.
Remember to export the files when you're done into a format supported by the mod.
All backgrounds except for crimenet, briefing, endscreen and loot are in 1600x900 resolution. Any lower and the background will bug out, any more and parts of it will be clipped.
crimenet, briefing, endscreen and loot are all 1280x720, and same rules apply.
Also included is a silly background package that I made to figure out which page is which, you can use it to find out the same.