This document presents an excerpt from the forthcoming book “Bulgaria 1879/1881 Issues” by Guido Craveri, offering a scientific and evidence‑based clarification of the long‑debated question surrounding the so‑called “Sofia printings.” The author, supported by experts in philately, paper conservation and modern forensic analysis, rejects the old hypothesis that these stamps were produced by bleaching and reusing original sheets.

The study introduces the concept of a Second Printing Plate, likely engraved in Saint Petersburg alongside the official plate, following the common Russian practice of preparing a backup plate. The characteristic curved frame line observed on certain stamps is interpreted as a deliberate design feature—analogous to known “secret marks” used by engraver Franz Kepler—rather than evidence of later manipulation.

A comprehensive spectrographic and structural comparison between the official printings and the so‑called “Sofia printings” demonstrates near‑identical ink composition, paper characteristics and engraving details. These results strongly indicate that both printings were produced at the same time or within a very short interval, not decades apart.

The document also includes a statement from A.I.E.P. expert Giacomo Bottacchi, who confirms that bleaching and reprinting on original paper is technically impossible without leaving detectable traces. No such traces exist on any known example.

Based on all scientific, historical and technical evidence, the author concludes that these items should be regarded as authentic, previously unissued impressions from a Second Printing Plate, deserving a legitimate place in collections of classic Bulgarian philately.