Banque du Congo Belge/Banque Centrale du Congo Belge et du Rwanda-Urundi, watermarked papers for 5, 10, 20, 50, 100, 1000 and 5000 Franc notes, as used on almost all Belgian Congo notes printed between 1912 and 1959, glued into individual blue card frames, annotations on paper, as produced, very rare, the 20 Franc paper being the only example in the Portals archive, and exceptional group (7 papers)
BNB B203-B315, Pick 8-35 for range of types £300-£400

Regardless of the design and date of the note, the same watermarked paper was generally used for each denomination, with the exception of the 5 Franc paper, which was used only on the 1924-30 issue (later 5 Franc notes had no watermark), and the 20 Franc paper, which was also used on several other Belgian-printed denominations (10, 100 and 1000 Francs), before production was moved to England.