'Ink' in the Bible

Then Baruch answered them, He pronounced all these words unto me with his mouth, and I wrote them with ink in the book.

being made manifest that ye are an epistle of Christ, ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in tables that are hearts of flesh.

Having many things to write unto you, I would not write them with paper and ink: but I hope to come unto you, and to speak face to face, that your joy may be made full.

I had many things to write unto thee, but I am unwilling to write them to thee with ink and pen: