In order for my "mod" to work you need this mod: https://modworkshop.net/mod/17160 - by Luffy.

After you have installed Luffy's mod, drop the folder "Mixed Synthwave Backgrounds" from my archive into "Assets" folder along the way: PAYDAY 2 > mods > MenuBackgrounds > Assets

I added 9 new images that are mine (well, not mine, but you know what I mean) and the rest is from mods of other people who I mention in the description. Also, I made versions of this mod for HD (1280x720), HD+ (1600x900), FullHD (1920x1080) and 4K (3840x2160) monitors. Maybe I'll make 2K version, but who knows...
WARNING: CHOOSE VERSION OF THE MOD THAT MATCHES RESOLUTION OF YOUR MONITOR, NOT IN-GAME RESOLUTION! THIS IS EXTREMELY IMPORTANT, AS I HAVE ALREADY ENCOUNTERED 2 PROBLEMS BY CHOOSING VERSION BELOW MY MONITOR'S RESOLUTION. Sorry for any inconvenience.

Some images I took from the mods of these people, so thanks to them for helping me with some magnificent images for this mod (although I didn't ask permission, sorry) and here's a link to their mods from which I took some images:
https://modworkshop.net/mod/31085 - by MurshK.exe
https://modworkshop.net/mod/28372 - by CaMpeR
https://modworkshop.net/mod/14348 - by TheMurphy^

Even though these images can be found on the Internet and freely used even without mentioning original author, I still wanted to credit these modders.
<3

Well, I hope you enjoy my pointless mod! :D