A.T. Robertson Commentary 3 John 1:13

"I had many things to write unto thee, but I am unwilling to write [them] to thee with ink and pen:" — 3 John 1:13 (ASV)

I had (ειχον). Imperfect active of εχω, when I began to write (γραψα, ingressive aorist active infinitive of γραφω).

I am unwilling to write (ου θελω γραφειν). "I do not wish to go on writing them.

With ink and pen (δια μελανος κα καλαμου), "by means of (δια) black (ink) and reed (used as pen)." See 2 John 1:12 for μελανος and Mt 11:7 for καλαμος, used for papyrus and parchment, as γραφειον (a sharp stilus) for wax tablets.