a drawing technqiue invented by Davinci,often called " painting without lines in a manner of smoke" Instead of painting sharp lines to separate the background from the subject, the chin from the neck or the eye from the face, It uses a soft, hazy and gradual blending to transition.
even though people were amazed by the Mona Lisa during those years, many artists have learned the technique and used it for decades resulting in the paintings we see now having sfumato and we are no longer impressed by Mona Lisa since there's a bunch of paintings with the same technique.
@Reddscope

