My first problem came when I was winding the yarn from the swift. Several times it just pulled apart and the affected area could be 5-8 long. Then it happened several times while knitting, a weak area would show up and it would just pull apart.
Besides being so cute they work well with everything from 'string bags' to socks. The points are my favorite shape, not too blunt. I bought 5 different sizes in the 16 length and have 3 projects working right now. The cords are very limber so they can be pulled out to continue for quite a while before changing to DP needles. Try one size and like me, you will probably be buying more !!!