Artists such as Leonardo Da Vinci used the golden ratio in their paintings because they believed that it created a more aesthetically pleasing composition. The golden ratio, also known as the divine proportion, is a mathematical ratio found in nature and is often associated with beauty and balance. It is believed that using this ratio in art creates a sense of harmony and balance that is pleasing to the eye. Additionally, many artists believed that using the golden ratio in their paintings helped to convey a sense of perfection and balance, which was an important concept in Renaissance art.