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Three‐dimensional (3D) printing appears to be a revolutionizing solid‐free fabrication (SFF) technique that grabs attention in recent years because of its inherent potential to transform virtual ideas into reality. Any manufacturing process involves a series of steps in converting the raw material into finished products. Manufacturing processes are classified as the additive process, subtractive process, formative process, and joining process (Bandyopadhyay and Heer 2018). As the name implies additive process involves the formation of an object by the addition of the material in a layered manner one above the other. On the other hand, the removal of the material by sculpturing an object out of the solid raw material is referred to as a subtractive process. In the formative process, the finished products are formed out of molten raw material as in the case of casting and forging. The latter is the joining process that combines the pieces of raw material either temporarily or permanently through fastening or welding. All the above processes other than additive manufacturing (AM) are grouped as traditional processing methods that involve a top‐down approach (Tofail et al. 2018). In contrast, AM represents a bottom‐up approach and is termed as a rapid prototyping (RP) layer‐based technique that involves the direct fabrication of physical objects from raw material (Figure 1.1) (Hon 2007). The International Organization for Standardization (ISO)/ American Society for Testing and Materials (ASTM) defined AM as the process of creating a 3D object out of a computer‐designed 3D model through deposition and fusion of material in a layerbylayer manner (Jiang et al. 2019). Several other terms that were used synonymously in place of RP and AM are free‐form fabrication, ingress manufacturing, layered manufacturing, and digital manufacturing. 3D printing is one such technique of AM that allows for layer‐by‐layer construction of 3D objects with minimal processing and less wastage of raw materials (McClements 2017).

Figure 1.1 Schematic representation of subtractive and additive manufacturing.

The ISO/(ASTM) 52900:2015 standard had classified AM processes into seven different categories based on its working mechanism as material extrusion (ME), binder jetting (BJ), material jetting (MJ), powder bed fusion (PBF), sheet lamination (SL), directed energy deposition (DED), and vat photopolymerization (VP) (Tofail et al. 2018). Among these 3D printing techniques, extrusion‐based 3D printing is the most commonly used technique because of its simplicity and low cost (Jiang et al. 2019). Before food printing, 3D printing technology has widely applied for printing polymers (plastics, resins, and photopolymers), ceramics, metals, biomaterials, etc., with the assistance of external (thermal or mechanical) energy. The feed supply of these materials can be either in liquid or solid material in the form of powders/sheets/filaments. The process involves the deposition of feed materials in their fluidic state and gets fused and bonded together through appropriate chemical interactions. Raw materials such as polymers can be easily melted and bonded together due to their low melting point and glass transition temperatures while metals and ceramics require higher temperatures that employ an external heat source either laser or electron beams for post‐deposition (Ligon et al. 2017). Each of the AM technologies has its advantages and limitations and the specific printing technique can be selected based on its applicability and end‐use requirements. With the present scenario, 3D printing is expected to reach a peak of inflation in the coming years and is predicted to receive the main focus during 2019 and 2024 (Jayaprakash et al. 2019). This chapter covers the digital advancements of printing technology and printers, potential advantage, and applications of 3D food printing over the traditional food processing techniques.