Nasty copy machine

Since I am usually teaching Friday morning and we are now dealing with really complicated diagrams, I thought it would be the best idea to use overhead projector films on which I could draw. So I went to the copy machine which has two trays with paper and just put the film into the first tray since the machine only tells you the tray it uses after it has copied ... And of course I got the copy on a normal sheet of paper because the copy machine took the paper from the second tray. Therfore I put the film into the second tray ... and the copy machine decided to take the paper from the first tray so I had another copy on a normal sheet of paper.
So I put films into both trays and almost expected that the machine would refuse to copy because it may not like film BUT it actually copied on film ... YEAH!