The quality of an anvil can be determined by several factors. Material is key - look for high-grade steel like the 8640 alloy used in Nimba anvils. The design should be well-balanced and practical, featuring both round and square horns, as well as a sizable face for forging. The rebound, or the ability of the anvil to bounce back a hammer, is another indicator. A good anvil should return at least 80% of the hammer's fall. Finally, the anvil's ring when struck lightly should be clear and not too high-pitched.