I did this while subbing a World History class last week. I had left it on the teachers desk while I greeted the students crawling in to class. One of them started to look at the cup really suspiciously. I told him, "you can grab it, no problem." He and a few others start to examine it with such a critical eye, I felt like I was trying to get it past a museum curator. Then they turn to me and say, "You did this miss?" I said yeah and they said, "you should be an art teacher". I chuckled and said "Maybe".