50 Sen

Indonesia's aluminum coinage of the late 1950s was produced under acute fiscal pressure — the young republic was hemorrhaging foreign reserves, and base-metal fractional coins were a practical concession to economic reality. The 50 sen denomination was losing purchasing power rapidly throughout this period as inflation accelerated ahead of the monetary crisis that would eventually force a currency redenomination in 1965, when 1,000 old rupiah were exchanged for one new rupiah.

The Schön 9.1 designation distinguishes this from later subvarieties by die characteristics documented in the series.