were colored and patterned in a similar fashion to late Czarist notes. In 1957, all these notes were reissued with the old date but modified design: because of the abolition of the Karelo-Finnish SSR, the number of ribbons on the state emblem was reduced from 16 to 15, and the nominal in Finnish was removed from the obverse. Sixth Soviet ruble, 1961–1991, (Identified as ISO code SUR) The 1961 redenomination introduced 1 new ruble equal to 10 old rubles and restated all wages, prices and financial records into new rubles. It differed from the confiscatory nature of the 1947 reform when banknotes were reduced to th of their value but wages and prices remained the same. Its parity to the US dollar underwent a devaluation, however, from US$1 = 4 old rubles (0.4 new ruble) to US$1 = 0.9 new ruble (or 90 kopecks). It implies a gold parity of Rbls 31.50 per troy ounce or Rbl 1 = 0.987412 gram of gold, but this exchange for gold was never available to the general public. Banknotes and coins of this series were designed by Ivan Dubasov. Coins The 1958 pattern series: by 1958, plans for a monetary reform were underway and a number of coin pattern designs were being experimented with before implementation. The most notable of these was the 1958 series, in denominations of 1 kop, 2 kop, 3 kop, and 5 kop in copper-zinc, and 10 kop, 15 kop, 20 kop, and 50 kop, and Rbl 1, Rbls 3, and Rbls 5 in copper nickel. These coins all had the same basic design and became the most likely for release. Indeed, they were mass-produced before the plan was scrapped and a majority of them were melted down. During this time, 1957 coins would continue to be restruck off old dies until the new coin series was officially released in 1961. This series is considered the most valuable of Soviet issues due to their scarcity. On 1 January 1961, the currency was revalued again at a rate of 10:1, but this time a new coinage was introduced in denominations of 1 kop, 2 kop, 3 kop, and 5 kop in aluminium-bronze, and 10 kop, 15 kop, 20 kop, and 50 kop and 1 Rbl in cupro-nickel-zinc. Like previous issues, the front featured the state arms and title while the back depicted date and denomination. The 50 kop. and Rbl