I wrote an article about the kosher/non-kosher status of shellac which is used in all forms of India Ink for a rapidograph.
I want to include also what HaRav Mordechai Eliahu said about it. I was told that it can be found in
אנציקלופדיה לכשרות המזון, להרב אדרעי, עמ' רנ
I don't know which volume. I don't have access to it in our little Shtaitle in Pennsylvania. Can someone in this forum maybe find it and post it here? Thank you.