Chinese coins were produced continuously for around 2,500 years by casting in moulds, rather than being struck with dies as with most western coins. Collectors can obtain affordable yet old, beautiful, and interesting coins associated with all the main periods of Chinese history. Many appreciate the fine calligraphy and the patina accumulated by these coins over the centuries. Numismatists find many challenges in attributing both ancient and comparatively recent coinage. The rise and fall of the quality of the coinage reflects the fortunes of the successive dynasties in Chinese history.