Potosí's cob coinage — macuquinas — existed purely to move silver out of the Andes as fast as the mints could produce it. Assayers at Potosí during this period were notoriously corrupt; the scandal of 1649 eventually exposed decades of debased coinage, though the worst fraud post-dated this Philip III issue. Half-real denominations saw the least scrutiny precisely because their small size made systematic debasement harder to detect at that weight.
Potosí's cob coinage — macuquinas — existed purely to move silver out of the Andes as fast as the mints could produce it. Assayers at Potosí during this period were notoriously corrupt; the scandal of 1649 eventually exposed decades of debased coinage, though the worst fraud post-dated this Philip III issue. Half-real denominations saw the least scrutiny precisely because their small size made systematic debasement harder to detect at that weight.