My commentary, 2018
I was bitten during a lesson.
A student stood up, ran across the room between the drawing tables -my back to the class room- held me by the waist and bit me from behind, close to the shoulder. And then she ran away.
At home, my wife asked what was that on my back. I looked in the mirror and there was the mark of the bite. I made a gesture of who was going to answer, but I gave up. It wouldn't help.
Other squares cut out of tracing paper were grouped side by side in rows and columns, making a background on which I superimposed a few others tracing paper squares, near the center. On them, in LetraSet, the word Cicatriz (scar) was drawn as the mark on my back. Then I made a blueprint, and added a seam with colored lines along the curve of the scar.