Originally Posted by Peckish

You are not messing up. Dunster is right - some batiks are stiffer and harder to handle than others.

A finer thread might help. I've used silk with success, but if you have a lot of different colors to match, I highly recommend getting one of those doughnut bobbin assortments of Bottom Line thread. It's fine (60 wt) and very strong, and much cheaper to buy than 10 spools of silk.