How do you get lines on tie dye?

To get crisp lines on a tie dye shirt, you have to "tie" it really tight with thick waxy thread called artificial sinew. 

This blocks the dye from getting to the fabric, as a resist tecnique. To tie the fabric, you actually don't make any knots. Just wrap the sinew around a handful of fabric about 4-5 times. Then pull it very tight, and the waxy thread locks down onto itself.

It stays tight on it's own so you don't need to worry about making any knots. 

To get it really tight, without hurting your hands, you can use something else as a pulling tool. I use a scrap piece of PVC pipe. I just wrap the sinew around the pipe a few times quickly, and then pull the pipe. The thread doesn't slip off the pipe and your skin stays protected. 

Spacing of the ties matters for dye absorption. If the ties are really close, you can get blotchy colors between the ties. If you are just starting, have a least 1.5" inches between the tie. You'll get the hang of it before spending an hour tying something that won't turn out well. 

You can see a video demonstration for tying geode style tie dye on my Youtube. 

Below are some examples of shirts tied with artificial sinew, in the geode style. If you need help or want to troubleshoot your process, you can join the Corky Dyes Facebook group.