Sail needles, like Beaverman said, have a body larger than the loaded eye. They're made that way to ease the passage of the needle through the hole. They also are very sharp and have almost a cutting edge on the corners of the body so no awl is needed.
Harness needles are dull and have round bodies. The loaded eye is as large or larger than the body so the craftsman must select an awl to make a large enough hole to allow the loaded needle to pass through the hole.
Glover's needles are for sewing the softest and thinnest of leathers with the finest of threads only and are bloody well useless for anything else.
I've sewn a bit of canvas and leather and much prefer sail needles and a sailmaker's sewing palm. Be aware if you're looking for a palm not to get a roping palm. Sewing styles are chosen for differing purposes. If your seam in leather must be watertight, a harness needle and suitable sized awl are necessary. If sewing clothing or articles not needing a water tight seam, a sail needle and palm are very much faster. Using a sail needle without a palm is a bloody, painful business. Fun to watch, though.
All this said, palms are harder to come by now than they were even twenty short years ago. No, mine is not for sale.
As always, your mileage may indeed, vary. Sometimes widely.
Three Hawks
Topic: Needle opinions? (Read 1250 times)