3D printing or additive manufacturing is a process that involves building a product layer by layer from a digital model using a material deposition or fusion technique. To achieve an optimal surface finish, you should use high-quality materials that are compatible with your 3D printer, ensure they are dry and clean, and use fine-tuned and calibrated 3D printers with high accuracy and precision which can produce thin and consistent layers. It is also important to use optimal print settings and parameters to reduce layer lines and artifacts, as well as appropriate post-processing methods like sanding, smoothing, or coating to enhance the surface appearance and durability. Digital manufacturing can help you improve your surface finish by providing advanced tools, data, and methods to design, produce, and evaluate your products. Consequently, you can increase product quality, performance, customer satisfaction while reducing costs, waste, and time to market - making digital manufacturing not only a trend but a necessity for manufacturing engineering in the 21st century.