When you look at the point with your naked eye, it looks like a regular round point needle. When you use a magnifying lens and look at the point you will see a tiny triangle point. Made for Quilting on Soft Leather:
When quilting you are doing "multi-directional" sewing. Using a wedge point will create irregular stitches because of the redirection of the sewing and the fixed angle of the wedge point.
The SD1 point will give you assistance to cut into the leather. The NY2 slender shape to the point will make a smaller hole, and the combination will avoid "bursting" holes through the leather.
(The PD/titanium finish makes the needle point more resistant to wear so it retains its sharpness longer).
The combination of the NY2 and SD1 point will give you the best performance quilting through leather.
The most likely needle sizes for quilting leather will be #18, 19, 20, 21, 22.What does Needle System NY2 Stand For?
(.PDF)What does Needle System SD1 Stand For?