4 penny postal stamp, imperforated trial printing in black blue gray on paper t in mixed franking with 3 Pfg and 6 Pfg - 12 Pfg postal stamps, variety "imperforated" on addressed cover, used "Erford 1 30.6.46", sound, photo expertize Dr. Michael Jasch BPP (2023) "genuine and immaculate", Michel 750.-