Diaphanous

diaphanous \dī-ˈa-fə-nəs\ adjective: 1. characterized by such fineness of texture as to permit seeing through {diaphanous fabrics}, 2. characterized by extreme delicacy of form; ethereal {painted diaphanous landscapes}, 3. insubstantial, vague {had only a diaphanous hope of success}

Etymology: Medieval Latin diaphanus, from Greek diaphanēs, from diaphainein to show through, from dia- + phainein to show

Diaphanous has many fine synonymous—gossamer, pellucid, sheer, transpicuous—but where plain talk is admired don’t shun the perfectly upstanding transparent.