Want to change the wallpaper on your CDE desktop? It's easy:

1. Convert your image to XPM format with the Gimp or some other image editing program
2. Copy the XPM file to /usr/dt/share/backdrops with a file name extension of .pm
3. Make sure file permissions and ownership are consistent with the other .pm files (in my case, perms are 444 and ownership is root:bin)
4. Use the Backdrop Style Manager to select the new image

There's just one catch - and it's a big one. The backdrop style manager chokes on large image files. By "large", I mean "bigger than about 113 by 88 pixels - the size of the SolarisLogo.pm image that's one of the default backdrop images.

Of course, I started out by trying this with an 8-meg image file; the poor little style manager utility chokes to death trying to start up with that image in the directory. I think it's trying to generate a thumbnail view, or something.

I created a new XPM image (72x72 pixels), copied it into the directory, set permissions to 444 and ownership to root:bin, and it works like a charm.

NOTE: The backdrop image is tiled, period. I don't see a way to center an image and only display it once.

Now, to see what the effective limit on image size really is..