As all art work
Exchanged by mail, the backside of an ATC should mention ( legibly written ) name and address of the creator !
An ATC should also be an original – or a part of a very small edition … As part of such an edition, it has to be
numbered ! ( F.e. : 1/5 = number one of an edition of five .)
– Artists know that it’s the same procedure as for multiples like wood-cut, lino-cut, a.s.o. .