I had this happen twice at the beginning of the year. I left my classroom full of students (they were coloring) and I walked to each classroom asking the teachers inside if they had my basket of scissors (I interupted their classes). I told them that I couldn't do anything because I didn't have my scissors. When I tracked them down I e-mailed the entire staff (including the principal) and apologized for interupting their classes, but explained that since I only see the students for a short amount of time each week and that I spend such a vast amount of class time preparing for each lesson that it is imperative that they ask my permission before borrowing my supplies. The second time it happened I had my 6th grade painting their clay with acrylic paint. Their classroom teacher had needed paint to paint their paper plates for some project and had borrowed my paint. I walked down the hall, past the office, and explained to the teacher that this paint was NOT tempera, it was expensive, and to please not borrow my supplies without asking. The principal was already upset with this teacher cause she spilled some of that acrylic on the new carpet. *evil laugh* I haven't had any problems since then. Course it doesn't hurt that I've been there longer than they have - seniority never hurts either. :-)
However, I am finding that my baskets are being used by the other teachers and not returned. (I guess my name label means nothing) When I go to use it, it is gone! Puts me in a sticky situation, because then I have nothing to use for the day. Does any one have this problem, and how do you handle it?