Which manufacturing approach adds material to create products?

• A. Air-drying
• B. Additive techniques
• C. Working drawings
• D. Photorealistic CAD-based models

Answer: (B)

Additive techniques involve building up a part by adding material, typically layer by layer from a digital model. This approach creates products by adding material rather than removing or reshaping existing material, which is the defining feature of additive manufacturing. Examples include 3D printing methods that lay down successive layers to form the final object, enabling complex geometries and customization with relatively little waste. By contrast, air-drying is just a drying/curing process, working drawings are detailed plans, and photorealistic CAD-based models are digital representations used for visualization, not actual fabrication. So, adding material to create products is best described by additive techniques.