Ink, Kosher vs. non-Kosher
We all know that there is no ancient source that requires ink to be מן המותר בפיך . Possibly, as said here before, because in the olden days ink was always מן המותר בפיך and the question was never raised. It was probably self-evident. Nowadays, no decent Rav will approve an ink which is not מן המותר בפיך . Who was the first one to raise this question? Was it raised because of animal ingredients or because of non-kosher wine?