Knob 208
This is a better design than 206 and 207 (from the same flooring sample), created with round and flat carbide tools, and round and flat files. It offers more finger space between knobs than 206, and a better grip than 207. The hole is threaded for a 5-40 set screw. After polishing the wood with very fine abrasive cloth, Kiwi neutral shoe polish over superglue finish the wood. The two images illustrate the resulting iridescence.
You can’t get a knob like this from plastic.