I just gave a carbon printing workshop in Philadelphia. Upon opening my suitcase at home I discovered a note saying my suitcase was opened and inspected. I am not surprised, considering the odds and ends I had in there for the workshop. They opened up my box of prints -- I hope they enjoyed them! I had a full box of 14x17 X-ray copy film in there -- totally toast, of course, but I am planning on fixing it out and using it as a support material for carbon tissues, so no problem. I carried a box of 11x14 film in my hand baggage, though!
Actually on the SF to Philly flight and back again, I felt more like a part of a load of cattle...This is because ferry companies treat their passengers as customers. Airports treat passengers as criminals.