How to make internal ribbon cane without grooves?
 

Hi,
I'm having trouble making a ribbon cane without grooves on the surface.
I've used the paddle and football method. Am I twisting too fast?
More practice? It's also hard to get it to be straight.
Any advice is appreciated.

I've only used ribbon cane on the surface, but when I got grooves was when I used glass with different viscosity (not COE, viscosity). So, if you're using clear of some sort and opaque of some sort, unless you melt them completely orange, you're going to get grooves. The trick is that when you melt to orange, it's harder to control the separation of color consistently. Lots of practice.

Thanks!