Creating bronze sculptures with undercuts or complex geometries presents unique challenges that test the limits of traditional metal casting techniques. The first major hurdle occurs during mold-making, where intricate negative spaces can trap molding materials, making it difficult to achieve clean impressions without damaging the original model.

The casting process itself becomes exponentially more complicated with undercuts. Molten bronze must flow evenly through these complex channels while maintaining structural integrity, often requiring specialized gating systems and multiple pour points. Complex geometries also create uneven cooling patterns, increasing the risk of stress fractures or warping as the metal solidifies.

Structural support becomes another critical concern. Unlike simpler forms, sculptures with undercuts often require hidden armatures or strategic weight distribution to prevent weak points from developing over time. Many artists must compromise between aesthetic vision and physical limitations, sometimes redesigning elements to accommodate the material's properties.

Modern solutions include 3D printing for precise wax models and computer simulations to predict flow patterns, yet even with advanced technology, the fundamental challenges of working with bronze's shrinkage rate (about 2%) and cooling behavior remain. These technical demands explain why historically, many bronze sculptures feature more simplified forms - the medium naturally resists extreme complexity.