mckwilter

I don't know if they're any good, but I do know that they are expensive. Just use two pins, one on either side of the seam.

If you have created your blocks correctly, the points will be at the 1/4" seam allowance; however, no one ever makes every point perfectly. In order not to lose the points of your triangles, place a pin in the point where the stitches meet on one block, then into the second block (if there's also a point there). Do that in every point. Then, when you sew, make sure your needle is a couple threads outside the points (a scant seam), and sew from pin to pin. You must use a scant 1/4", because when you open your blocks, if the needle has gone exactly into the points, the thickness of the thread will take up a thread or two and the points will disappear.