Photo Engineer
Subscriber
Ink would not be on the film, but the backing paper, although that would result in solvent issues, although these days, many inks are water based and should not give a problem.
Paul;
When wound on the spool, the film emulsion is in direct contact with the backing paper and the inked information. All inks must be tested for transfer properties. Chemicals can migrate via that contact.
I have seen other mfgrs products with the imprint of the numbers and other information on the emulsion due to just such contact.
"Should not" does not assure "will absolutely not" and therefore would have to be tested in a wet oven, and a dry oven for several weeks and at ambient for up to one year before validation of the ink.
Kodak uses a special ink and glue on the tape and backing paper to prevent such problems.
PE