100 Francs green reverse

Constant Montald was a prominent Symbolist painter, and his involvement in designing banknote artwork for the National Bank was part of a broader Belgian effort to elevate the visual quality of its currency in the early twentieth century. Édouard Biet's engraving translates that aesthetic ambition into intaglio — a demanding conversion from a painter's idiom into a printmaker's.

P#70 spans a two-year window, 1906 to 1908, after which the design was retired in favor of updated plates. The Brussels printing works had been operational since 1851, giving the Bank unusual in-house control over production security that most contemporary European issuers still outsourced.