A couple of years ago, a friend of mine needed a karate belt rack for her son who had begun racking up the belts in his karate class (pun definitely intended). The racks available on Amazon were of suspect quality, so I made one for them out of maple.
Two years later, she has another son who is also racking up the belts (puns are funnier the second time), so I made him a contrasting one out of walnut.
If you’re interested in making one yourself, each slat is 14″ wide, 1.5″ tall, and 5/16″ thick, and I chamfered all of the front-facing edges. They’re spaced about 7/8″ apart, and the boards that they’re glued and pin-nailed to (from the back) are 1/2″ thick and 1.5″ wide. The entire rack is about 51″ tall, large enough to display twenty belts.