Pieces are a type of graffiti. Their name is short for "masterpieces". Pieces are a big and very detailed type of graffiti made with letters.
They are one of the main types of modern graffiti, along with tags and throw ups. People who usually don't like graffiti are less likely to dislike pieces[1] and people are less likely to call them vandalism.[2]
Because they are so large, pieces are usually made with spray paint, but people also use paint rollers.[1]