This step shows you how I made the billiard balls. Only classic Knex balls with holes in them will work.

First, for the striped balls I lined a piece of regular masking tape up with the center of the hole in the ball. (pic 1) Then I wrapped the tape all the way around the ball. (pics 3-5) After that, I painted the exposed sides. Once the balls dried I peeled the tape off and taped the painted sides. (pics 6 and 7) For the solid colored balls I just painted one side, let it dry, flipped it, and painted the other side.

To paint the circles with numbers in them I first took a chunk of wood and made some Xs with masking tape. (pic 8) After that I took a dime, put it in the center of the each X and drew a line around it with a pencil. (pics 9 and10) Next I took my pocket knife and cut out the circle. (pics 11 and 12) Once all that was done I peeled off all the Xs and put 2 of them (pics 13 and 14) on each ball opposite of each other. Once the circles were done drying I hand painted the numbers on. There you have it. That's how I made the Knex billiard balls.

P.S. Some balls take more coats of paint than others. For example, the green and blue balls needed only 3 coats of paint. While the purple and orange balls needed 5 coats of paint. If you are going to paint Knex balls I recommend buying the color yellow, because it's easier to paint over.

*KneXtreme*