[micrex22]

I thought it'd be useful to publish info on how to get a custom wallpaper/background/backdrop or whatever you want to call it, on AIX's native CDE.

1. Create your backdrop the size(s) of the monitors you'll be using it on, like 1600x1200 or whatever
   
2. Reduce the colour of the final image to 80 colours or less (save as PNG format as JPEG will re-encode and add more colours again)
   
3. Convert the outputted colour reduced PNG to a XPM (i.e. yourimage.png to yourimage.xpm)
   
4. Rename yourimage.xpm to yourimage.pm (apparently AIX CDE references .pm instead of .xpm, even though they're the same thing)
   
5. Copy it to: /usr/dt/backdrops
   
6. Edit the desc.C text document with another definition for your image (yourimage.pm) now added to the catalogue
   

Once that's done your custom background will work flawlessly and you'll be able to choose it in the background selector: