Orchestra folders (Pads) can be easily and inexpensively assembled by you in your library.  This is one of the methods that can be used after you have had your cover stock prepared.  Railroad board or other heave cover stock can be purchased from your local paper supplier or art supply store.  It should be cut to 11x14 inches.  This will accommodate almost any sheets of music.  By using a heavy book tape, tape two panels together and put the name of the instrument on the outside using the mail merge feature of your computer word processing program.  Leave space between the covers to allow for expansion.