It's wrong to waste school supplies.
Maci is a student who enjoys using her school's art room to paint as they provide all necessary supplies at no cost to students.
Maci wants to paint a canvas in the art room.
Unsatisfied with her work, Maci paints over the imperfections on her canvas.
Unsatisfied with her work, Maci discards over 40 canvases before keeping one to work on.
Maci ends up with a piece she likes, and the other students have canvases to use.
There are no canvases left for other students to use.