Description and research notes
Color-trial specimen of the 1970 100 Francs printed in an experimental blue palette rather than the adopted green, with red SPECIMEN overprint and punch cancels. Serial A000000. PMG 58 EPQ Choice About Unc.
Color trials were more than aesthetic tests—they measured legibility under mechanical cash-sorters and visual distinction beside Belgian denominations. De La Rue engineers varied tone density and fluorescence to ensure anti-counterfeit stability across different lighting. This surviving sheet reveals the laboratory logic behind a working currency shared by two countries but printed in separate facilities. Together with the gridline specimen and photo proofs, it shows the complete production chain from design concept through full press calibration, a luxury few collectors can document within one national portfolio.