It all depends on the thread you are using. 50wt 3ply, 40wt, thread usually take a 90/14 needle. If the thread is 50wt 2 ply or 60wt you need a size 80 and over 60wt you may have to go to a size 70. There are several sizes of 90 needles. I use topstitch needles for all my piecing and machine quilting.
This probably won't apply to you but once I was so frustrated that my needle kept coming unthreaded no matter what I did. I was threading it right to left instead of left to right. LOL.
Last edited by BellaBoo; 07-26-2012 at 11:12 AM.