Most Iroshizukus tend to have high pH [1]. It might be problematic on e.g. celluloid pens depending on the particular ink color you use. It's a shame as they ar

Most Iroshizukus tend to have high pH [1]. It might be problematic on e.g. celluloid pens depending on the particular ink color you use. It's a shame as they are superb inks. I tend to use J Herbin Lie de Thé which is close to neutral and its formula is very safe (basically water plus food-grade colorants). [1] http://www.richardspens.com/?page=ref/care/ink_ph.htm http://www.richardspens.com/?page=ref/care/ink_ph.htm