For a simply connected polygon , convexification is the process of taking the convex hull of and then, for any side of that is not part of , reflecting the part of inside over the segment . Iterating the process eventually leads to a convex shape.

Z. A. Melzak conjectured that a given iteration of the Koch snowflake requires the greatest number of convexifications to make a convex figure, compared to other figures with the same number of sides.