Watch List notes:

Costa Rica: 20 Colones ND (1983) Tyvek Proof of P. 252(p). This note is rare as it was printed on a so-called hybrid banknote substrate "Tyvek" which was tested by the American Bank Note Company for banknote circulation in the early 1980s. The results of circulating the notes were not convincing for the printing works so they returned to normal paper later and closed the Tyvek banknote production. This is what makes this piece an interesting and rare one. The set consists of 2 Proofs. One with complete print (but without serial and signatures), the other one only shows the underprint of both sides. Condition: UNC.