Door knob insert shims

I've got a house full of beautiful door knobs.

But these knobs were impossible to center in the first place and even once centered kids hanging on them caused them to wiggle loose and move up and down over time.
This destroyed my door paint (even though nice paint is a lost cause since I have kids in the first place).

So, to fix my problem -- after repainting the doors -- I've created inserts to center the door knobs and stop the movement.

I just installed 6 of these inserts in my hous