Euro coins edge of the €2 coin also protects it from counterfeiting. Euro coins were designed in cooperation with organisations representing blind persons, and as a result they incorporate many features allowing them to be distinguished by touch alone. In addition, their visual appearance is designed to make them easy to tell apart for persons who cannot read the inscriptions on the coins. The coins increase in size and weight with value. Of the eight denominations of euro coins, the three lowest denominations are small, resemble copper in colour and are quite thin and light. The next three denominations resemble gold in
2 euro coin entry of Slovenia. Hence, the Slovenian design was added to the designs in circulation. Cyprus and Malta joined in 2008, Slovakia in 2009 and Estonia in 2011, bringing four more designs. Also in 2009, the second eurozone-wide issue of a 2-euro commemorative coin was issued, celebrating ten years of the introduction of the euro. In 2012, the third eurozone-wide issue of a 2-euro commemorative coin was issued, celebrating 10 years of euro coins and notes. In 2015, the fourth eurozone-wide issue for this denomination was issued, commemorating the 30th anniversary of the Flag of Europe. The coins are composed of