Background: Edward Henry Weston (March 24, 1886 - January 1, 1958) was a 20th-century American photographer. He has been called "one of the most innovative and influential American photographers..." and "one of the masters of 20th century photography." Over the course of his 40-year career Weston photographed an increasingly expansive set of subjects, including landscapes, still lifes, nudes, portraits, genre scenes and even whimsical parodies. It is said that he developed a "quintessentially American, and specially Californian, approach to modern photography" because of his focus on the people and places of the American West.
Context: Weston always made contact prints, meaning that the print was exactly the same size as the negative. This was essential for the platinum printing that he preferred early in his career, since at that time the platinum papers required ultra-violet light to activate. Weston did not have an artificial ultra-violet light source, so he had to place the contact print directly in sunlight in order to expose it. This limited him to printing only on sunny days.  When he wanted a print that was larger than the original negative size, he used an enlarger to create a larger inter-positive, then contact printed it to a new negative. The new larger negative was then used to make a print of that size. This process was very labor-intensive; he once wrote in his Daybooks "I am utterly exhausted tonight after a whole day in the darkroom, making eight contact negatives from the enlarged positives."  In 1924 Weston wrote this about his darkroom process, "I have returned, after several years use of Metol-Hydroquinine open-tank" developer to a three-solution Pyro developer, and I develop one at a time in a tray instead of a dozen in a tank." Each sheet of film was viewed under either a green or an orange safelight in his darkroom, allowing him to control the individual development of a negative. He continued to use this technique for the rest of his life.  Weston was known to extensively use dodging and burning to achieve the look he wanted in his prints.
Question: How did he use this technique to his advantage?. Whats the answer?
This was essential for the platinum printing that he preferred early in his career, since at that time the platinum papers required ultra-violet light to activate.