Translation for "back-of-the-envelope" to spanish

Back-of-the-envelope

• reverso del sobre
• back-of-the-envoltura

Translation examples

reverso del sobre

There was a faded postmark from New York, and on the back of the envelope, a post office box somewhere upstate.
Había un matasellos desvaído de Nueva York, y en el reverso del sobre, un apartado postal del interior del estado.