I bought a bunch of these magnets to hold boards down flat on the Glowforge. I figured I may as well try making a magnetic knife block.
The top plate is Proofgrade medium maple hardwood, with a very deep manual etch (500 speed at full precision power) for the magnets, to thin out the board and register them. They are a little over a millimeter deep.
Then comes some fully cut out 1/4" plywood:
Followed by another piece of 1/8" maple hardwood for the back plate. I ended up reusing a piece I had inadvertently etched the wrong diameter into, but that all ended up on the inside so no problem.
I put the magnets in and glued the top and center segments together. The magnets serve to register the parts, which makes it easy. Big tip: work over a steel baking sheet, or the magnets can come flying out of their holes and join in a big group hug, and you will probably shatter a few. Ask me how I know.
I epoxied the magnets in place for security:
Then glued on the back plate. Sanded the edges and finished with food grade mineral oil. Mounting will be with 3M Command Strips onto tile, or I would have made provisions for countersunk screws.