I bought a set of Aurifil 40w poly 1000 yard cone for machine quilting. I am using Superior Bottom Line for the bobbin. The thread was shredding so I knew the needle was too small. I put in a bigger size and the thread was breaking. I put in a bigger size needle and the thread kept breaking. After looking at all the what size needle to use with what type thread I had used all the sizes that said to use. I found a package of Organ Size 100/16 needles I had never opened. I put one in and my thread loves it. No more breaking or shredding. No where on any chart do I find that size needle recommended for 40wt poly thread! Matching thread to needle for machine quilting seems to be one big crap shoot. :lol: :lol: :lol: