Does anyone know where I might be able to purchase plain white A4 printer paper with a perforation down the middle (so it tears easily into two A5 pieces)? neb: An indirect answer, but if there's not ...

Paper cutters can cut both ways: A really good one will make a project much more streamlined, and the end product more attractive, but a so-so cutter will add time and result in a sub-par product. But ...