For typical 3-4m ceiling heights and 1.5-2m viewing distances, position fixtures at 30-35° from vertical (incident angle). Calculate: if fixture at 3.5m height, artwork center at 1.5m, fixture should be 1.2-1.5m from wall. Light reflects to floor, not eyes. Provide fixture position templates based on ceiling height. Use adjustable fixtures to fine-tune for specific works. Test with actual glazed works at exhibition installation. For very reflective glass, consider reducing angle toward 25° or specifying anti-reflective glazing.