I've noticed people saying (often citing Richard Binder's site) that heavily alkaline inks are not to be used in celluloid pens, as they can cause damage or "melt" the body. From what I've seen and searched, there's no real threshold for an ink to be alkaline enough to dissolve celluloid. Some consider pH levels up to 8.0 or 9.0 to be "neutral," but how safe are such pH levels truly for celluloid? Say, if I want to put Iroshizuku or a Sailor ink in a Vacumatic, what can I expect? What about Waterman Red or Noodler's black (assuming I wasn't worrying about staining), which are both slightly alkaline, around high 7s or low 8s? -Bogdan