De La Rue, which was also producing karbovanets banknotes until the started operation in 1994. However, by the time the banknotes arrived, the economic crisis became so deep and inflation so bad that it was decided to stick with karbovanets. It was only on 2 September 1996 that the first series of hryvnia banknotes (though only up to 20 hryvnias) was introduced into circulation by the National Bank of Ukraine (NBU). Also in 1996, the 1, 50, and 100 hryvnia notes of the second series were introduced. 1 hryvnia note was already produced in Ukraine in the brand new printing factory (as would all subsequent banknotes), while the two higher denominations were still printed by De La Rue and had better security features in comparison with the first series. Most of other denominations went to circulation the following year. 200 hryvnia note, which was seen at the time as worth too much, was only released in 2001, just before the tenth anniversary of Ukraine's independence. The second series, however, was quickly found to have several drawbacks, so plans to replace it were approved as early as in 1999. Serhiy Tihipko, then governor of the National Bank of Ukraine, noted that 2, 10 and 20 hryvnias were hardly distinguishable from each other. Artists have also pointed to several design flaws and inaccuracies in the banknotes (Lopata was, for instance, not happy with the De La Rue banknotes), and the National Bank of Ukraine wanted to introduce new security features. Thus in 2003, ₴20 note became the first banknote of the third series of the Ukrainian hryvnia; other denominations quickly followed suit. It was also then that the ₴500 bills, which became among the most common banknotes in Ukraine, were introduced into circulation. Refurbished versions of these banknotes, with even more anti-counterfeiting techniques, were released starting from 2014 (₴100), followed by ₴500 regular issue and ₴20 commemorative note in 2016, ₴20 regular bill in 2018 and the rest of the banknotes (including the new ₴1000) in 2019 and early 2020. Current state Since October 2020, all banknotes from the first and the second series are withdrawn from circulation and are only exchanged in banks. In addition to that, banknotes from ₴1 to ₴10 are being substituted by a new set of coins, but, like all the other banknotes of the third series and all banknotes from the fourth series, these still remain