I bought a package of different colored Foam Sheets at Hobby Lobby. They come in a bunch of different colors (I got the primary colors pack). I bought the 50 piece sheets pack measuring 5 1/2 x 8 1/2. It was $4.99, but on sale for 50% off!! That's really cheap for pop dots.
I experimented with the black foam first. I cut multiple strips about a 1/4 inch wide each. (My son is helping me cut in this picture.)
Then I lined them up in my Xyron sticker maker and ran them through.
Then I flipped them over and ran them through again on the other side.
I made some cuts by hand so I have a small pop dot in a pinch. But the great thing is that you can cut any size or shape pop dot you need.
If you're making a card with some black shadowing or black images, when you use the black pop dots you don't see them!! Check out my last post to see what I'm talking about.