All I needed was a push in the right direction to drop the Gimp for screenshots, and start using scrot. It’s just what I wanted: A tiny command-line-driven method for punching out a screenshot, with a timer delay and a few other options.

Ordinarily I end up installing the Gimp, taking the screenshot, then uninstalling the Gimp — just because I hadn’t looked into a better way of doing it. Thanks to BLTicklemonster for mentioning it here. Another good reason to keep an eye on the IceWM thread.