People have written tutorials about them, which you have to pay for.
It has surprised me because I have tried to make them after an free tutorial on the glassforum Lampwork.etc..... this tutorial was made in the year 2008.
Anyway, here are some pics of my experiments with them....
They are not my most favorite beads to make, but it's always fun to experiment.
From tomorrow I will close my Etsy shop because we are leaving to the East of Germany for an week, to enjoy our vacation. I hope the sun will shine all week long, because unfortunately it looks like we are having autumn right now. See you later! Bye!