The antonyms for "most sketched" would be words that indicate a lack of sketching or drawing. Some possible antonyms include words like "unsketched," "unillustrated," "unpainted," or "untouched by the pencil." These words suggest the absence of the creative act that produces sketches, drawings, or illustrations. While "most sketched" implies a high frequency or abundance of sketching, these antonyms suggest a void or emptiness in that regard. Of course, the absence of something can be just as important as its presence, and it's important to remember that art takes many forms, not all of which involve a pencil or a piece of paper.