Dripstone Copper Guide (Java)

The Dripstone Advantage

While copper spawns everywhere, it has a special relationship with Dripstone Caves. In this biome, the size and frequency of copper veins are significantly increased.

If you see pointed dripstone or stalactites, start looking at the walls. You will often see multiple copper veins in the same room. It's the most efficient way to farm copper without a dedicated drowned farm.