A NAIL BREAKS AT THE CORNERS, NOT AT THE TIP
A corner of the free edge is where the outline changes direction abruptly, and that is exactly where the edge catches on fabric, on a pocket, on a door handle. A square carries the full width of the bed all the way to the edge, which gives it the greatest support of all eight shapes, and at the same time gives it two such corners. A soft square is the same square with only the corners taken off: ninety-four per cent of the width remains and no snagging remains at all.
Narrowing is paid for in width. Almond and stiletto are filed into the sidewalls, and the sidewall is precisely the width that carries the overhang. A stiletto keeps under a millimetre at the edge over a centimetre of free edge; a point like that does not hold on a bare plate, which is why these shapes are worn under gel or acrylic rather than on their own.
Overhang costs time. A fingernail grows about 3.5 millimetres a month, and a toenail about half as fast at roughly 1.6, so eleven millimetres of free edge for a stiletto is about three months during which it must not break once. A round edge of 2.4 millimetres grows back in three weeks.
