Used various combinations of curly maple, Purple Hear, and walnut to make these.
Got the magnets from ebay. I use approximately 10 or 11 one inch round rare earth magnets in each (see photo of back of the boards) which is seems to be the correct amount to hold the boards up on refrigerator and to catch the falling caps.
The magnets used to catch the falling caps are approximately 1/16th of an inch below the surface. I fill in the holes with 1” dowels glued.
Too bad I can’t post video or else you could see this in action.
Another simple to make gift that people really like. Hmmmm possibility for Beer Swap?