Below,

is an answer, 

to the Travelling Salesman Problem, a mathematician who teaches at Oberlin, Dr. Bob Bosch, created this image of Botticelli's Birth of Venus using the shortest possible line while still rendering the image, yes it is made of just one single line, a masterful illustration of the Travelling Salesman Problem, the Oxford Dictionary of Psychology defines it as:

The problem of finding the shortest path that passes through a set of given points once and only once, as when a travelling salesman needs to visit a number of specified cities exactly once, using the shortest possible route. The problem is notoriously difficult to solve, because the number of possible tours rises rapidly with the number of cities.

for more of these remarkable drawings have a look here, and for more from Dr. Bosh have a look here, amazing!