Creating a peened surface on bronze sculptures is a specialized technique that adds texture, depth, and visual interest to the artwork. This process involves mechanically deforming the metal surface to achieve a dimpled or hammered appearance. Here are the most common techniques used by sculptors and metalworkers:

1. Hand Hammering: Traditional and labor-intensive, this method uses a ball-peen hammer or specialized texturing hammers to strike the bronze surface repeatedly. The size and shape of the hammer head determine the pattern.

2. Shot Peening: Small metallic or ceramic beads are blasted onto the bronze surface at high velocity, creating uniform dimples. This technique is efficient for large areas and provides consistent results.

3. Chasing and Repoussé: A combination of hammering from both the front (chasing) and back (repoussé) of the bronze sheet creates intricate raised and recessed designs.

4. Power Tool Peening: Rotary tools with textured bits or pneumatic hammers speed up the process while allowing for controlled patterns.

5. Chemical and Heat Texturing: While not strictly peening, combining hammering with patinas or controlled heating can enhance the peened effect.

Each technique offers unique aesthetic possibilities, from subtle matte finishes to dramatic tactile surfaces. The choice depends on the desired effect, scale of the sculpture, and artist's preference. Proper execution requires skill to avoid overworking the metal or creating stress points that could lead to cracking.

Artists often combine these methods with other bronze finishing techniques like polishing, patination, or waxing to achieve the final desired appearance. The peened surface not only adds visual appeal but can also help hide minor imperfections in the metal.