1947: Postage Dues

The first and only postage due stamps of the Republic era were issued on October 20, 1947 as a set of four values.

Quantities printed:
3c carmine (500,000)
4c blue (400,000)
6c olive (300,000)
10c orange (300,000)

Printing method: Engraved
Printers: American Bank Note Company
Perforation measurement: 12
Unwatermarked paper

If not stored properly, the 10c is prone to oxidation; the orange ink turns to brown and eventually to black.

[Data taken from various sources.]