One of the enduring anomalies of philately is the tradition of expert’s signatures. Quality, more than rarity, determines price. So it seems odd that so many rare stamps are indelibly marked in ink on the reverse to signify their genuineness or quality when such marks, if made by anyone else but the expert, would be deemed a significant fault. Owner’s handstamps (where the owner identified his stamps by placing his initials or name on a rubber stamps and stamping his property) were common in the Nineteenth Century and today these are considered faults by collectors. But expert’s handstamps, which look the same, are not considered faults and even add significantly to the value of the stamp that they are on.
This philatelic tradition of expert’s signitures comes to us from Central Europe where there was a real forgery problem in the late Nineteenth Century. The old German and Italian States had been absorbed into larger nation states and scores of previous sovereign political entities no longer existed. Hundreds of German and Italian States stamp types were demonetized. These stamps had no postal validity or value and so whatever counterfeiting laws existed at the time either did not apply or were loosely enforced. Fraud laws were still applicable but, because the state had no interest in preserving revenue, these claims were rarely pursued. But there was still strong philatelic demand for these stamps. It was this collector demand that led to the earliest handstamp guarantees, probably the Senf Brothers, about 1870 (photographic certificates were prohibitively expensive in this period). A stamp with a “Senf” signature on the back was the surest and most inexpensive guarantee of genuineness. Collectors, especially in the German speaking world grew up with this tradition of signatures and it has remained in place even today. Thus you have the anomaly of a German expert certifying the fact that a stamp has perfect gum by marking the gum in ink.
