I've never used a tool to marver and make them round because I don't like the pits it makes in the surface with many of the frits I use. Especially with graphite. When the pits are there, you can't make them disappear with more heat and sometimes they get worse.
So, because of that I only "eyeball" them. I did a tutorial a long time ago and while this is geared toward the newbies, it's good for anyone wanting to learn to make them with the best tools for the job - heat and gravity.
Here's the tutorial:
http://www.lampworketc.com/forums/sh...ht=round+beads
Some spherical round beads I made so long ago and I forgot when:
I hope you find that helpful!
