Actually, a lot of our repertoire is on IMSLP (as an org the orchestra doesn't have heaps of money, so "stuff that can be borrowed from a library or printed out cheaply" is A Significant Concern). NEVERTHELESS you are quite right about pencils etc, so we only tend to work from phone/tablet displays of IMSLP downloads when we've screwed up and not managed to print/bring all the parts for all the instruments present...