Hi,

Whenever I have needed them in quantity I have been forced to make them with a
router jig. The cuts are never smooth like you see at the big box store, perhaps
due to my being in a rush whenever this need occurs and surely for using
inferior materials, but as we say in theatre, they’ll never notice it from the
3rd row!  If you’re doing fine work and have time to spend fettling the
router/jig setup then you can probably do pretty well with a little practice.

John