In 935 the Koryo dynasty was founded, and lasted until 1392. Koryo's rulers continued to adopt Chinese ideas but worked to maintain distinct Korean features. For example, Koryo adopted a civil service examination system similar to China's. In Korea though only nobles could take the test, and government officials were inherited. Korean culture thrived, and Korean artisans created pottery covered with a blue-green glaze called celadon. Koreans used Chinese methods of printing and carved 80,000 wooden blocks to print Buddhist texts.