I learnt a valuable lesson today - don't use cheap cotton! I was making lavender bags, as already blogged about and sewing a scallop stitch around the edges. The machine uses a double needle for this stitch and you therefore have to use two seperate cotton reels.
One reel was a Gutterman thread and the other was a cheap cotton I picked up in the craft shop. There was a more expensive one available but I was feeling like a cheapskate, so bought the reel that was about 30p less. Big mistake! I lost count of how many times the cheap thread snapped. The faster I sewed, the less the cheap cotton could withstand the strain.
It was really frustrating and completely my fault for buying the thread in the first place. It was interesting using the two threads side by side though as it highlighted the quality difference which I might not have appreciated otherwise.