Reply by Dan Lyke

Make the drawer bottom and sides thicker: ¾” ply should be just fine supported on all 4 sides over a 23” span.

The only concern I’d have would be the door canting sideways and jamming. When I built a shallow pantry cabinet for my kitchen I decided to go with drawers that weren’t 2.5 times as wide as they were deep because I experimented and decided they’d give the slides I was using problems, but I think 23”x20” should work just fine with most slides.

-- Dan Lyke, Petaluma California, http://www.flutterby.net/User:DanLyke