Nowadays you can buy these but you don't have to. You can build one from scrap.
2 pieces of 1/4 round molding, 1 1/2" and 3/4", with the round surfaces facing each other, covered with a 1/4" thick piece of soft foam rubber.
You need the 2 different sizes of molding so you will have a choice of angles to hold your Customs at.
Nail or glue the moldings to a flat board, then cover the whole thing with the foam rubber. Now, tuck the foam rubber in between the moldings and staple it down.
Now, cover the whole thing the same way with a slick fabric.
I use satin, or a nylon fabric. You want it slick to avoid fibers and strings that will attach themselves to your Customs.
It also makes it easier to wipe down after it's been sitting aside for awhile.
