Final answer:
The convex blade is considered the best overall edge for a hair stylist because it is the sharpest and provides a smooth cut, which is optimal for precision haircutting techniques.
Step-by-step explanation:
The best overall blade edge for a hair stylist is convex, because it will give you the smoothest cut and is the sharpest edge possible. Scissors with a convex edge are expertly designed for slicing through hair smoothly, thus ensuring a precise and clean cut. The design of the convex blade allows for a sharper angle on the cutting edge which makes them ideal for techniques like slide cutting and point cutting used commonly by professional hairstylists. Other types of edges like beveled, serrated, or concave are not as sharp as the convex edge and are used for specific purposes rather than general hair cutting. For example, serrated blades are often used to add texture or grip the hair, and beveled edges can be useful for layered cuts. However, for overall sharpness and a smooth cut, the convex edge is superior.