No. 519 - arriving mail art "Am 9. Mai ist Muttertag" from Heinz W. Lotz (Germany)

No. 519 - arriving mail art "Am 9. Mai ist Muttertag" from Heinz W. Lotz (Germany) - another postal experiment by Heinz, using an official postal document without a valid postage stamps on it. The collage came without any problems. Thank you very much.