Diamond Shears
This age old design is now available in a size geared to flameworking. The blades of these shears are each shaped with a large "V" in them. When the shears are closed onto hot, pliable glass they form a square or diamond around the glass, contacting it in four spots. Squeeze the shears a little and the glass uniformly constricts. Close the shears all the way and the glass is cut clean.