Triangle needle also known as cutting needle as the points are sharp knife like. Commonly use in surgery as suture needle that cut through the skin. This triangle cutter needle perform the same function in leather craft as it leaves a triangle cut for the waxes thread to slot in wedging tightly with less sliding. Overall a triangle needle stitching will be tighter and possibly neater with flat braided waxed thread.
Sharpening is easy with the flat side placed firmly on a mesh #2000 sand paper taped onto a glass plate. With a drop of water or oil, all three triangles can be sharpened knife sharp. Needless to say a sharp needle is much easier to penetrate the leather thus omitting the requirement of prepunching holes which in most cases are too oversized for a tight stitch. Jabbing the sharp needle point into a beewax block helps for better penetration especially if leather is thick. A neat handstiched leatherware do add value to workmanship.
