Thread is a major concern. Make sure it's fairly new and good thread. Also your needle should be changed about every 40 hours worth of work. Make sure the needle is the right size for the cloth your working with. If it was an anywhere problem on the same cloth, I would say you got some poor quality cloth. I always take a little magnifying glass with me to be able to check how close the threads are in the cloth itself. Checking thread count. If it's not good quality higher thread count the seams will pull apart.