Ink was the everyday writing medium in the ancient world, made from soot, gum, and water. Paul contrasts Spirit-written hearts with mere ink on stone (2 Cor 3:3). The elderly John twice closes letters by saying he'd rather speak face-to-face than write 'with ink' (2 John 12, 3 John 13). The Greek glosses across languages consistently render this as 'ink' or 'with ink,' reflecting the straightforward material reference.