Most art teachers stress the importance of lost and soft edges in paintings to allow the viewer’s eye to travel through the painting. My natural tendency is to make hard edges, so it was good to learn that one can have lost hard edges by having some shapes around the subject that are similar in color and value to the subject. However, soft edges are encouraged.
Christopher Schink uses an elephant ear sponge to soften edges. I just got a brand new elephant ear sponge, so I got out some newer, not-so-good paintings to experiment on. (I had no old ones, due to my habit of throwing them out -- see below.) I smudged away, and I think I greatly improved the paintings. But I couldn’t stand it and put some edges back. Still, it was great fun to play this way, taking away, putting back. Here are the comparisons, all hard edges first, smudged edges second. Note that smudging the edges spread paint around and changed the colors.