Wall mounted bracket for spools

I've designed this simple wall mounted bracket to help me organise all my spools. There are two versions. One metric which works with a standard 18mm wooden dowel and one imperial which works with standard 3/4inch dowel. Both of those dowels are standard issue in any hardware store. You mount it using M4 screw/bolt. I would suggest printing an extra bracket every 7th spool, so roughly every 58cm. I mounted my bracket on the side of Ikea Alex cabinet and it happily takes 7 spools with no issues.