Two of the most widely used technologies in today’s desktop 3D printing market are fused deposition modelling (FDM) and resin-based printing. Although common assumptions are often made about their differences—such as FDM being more affordable and resin printing offering finer detail—there are several important factors to consider before choosing one over the other. These include the underlying technology, materials, strengths and limitations, cost, and intended applications.

FDM 3D Printing Technology

FDM is a type of additive manufacturing that belongs to the “material extrusion” category. As the name suggests, printers using this method create objects by extruding material along a defined path. In FDM printing, this material is typically a thermoplastic filament, sometimes combined with other materials.

The process is similar to using a hot glue gun: a solid filament is fed into a heated nozzle, where it melts and is deposited in thin, flat layers. These movements usually follow the X and Y axes of a Cartesian coordinate system. The first layer is laid onto the build surface and rapidly cools and solidifies. Subsequent layers are deposited on top, gradually forming the object layer by layer.

Resin 3D Printing Technology

Resin printing refers to a group of additive manufacturing technologies based on polymerisation. Most resin printers use a container, known as a vat, which holds a liquid, photosensitive resin. This resin hardens when exposed to ultraviolet (UV) light. A build platform is lowered into the vat, and a light source beneath the transparent base cures the resin in a specific pattern, attaching the first solid layer to the platform.

After each layer is cured, the build platform lifts slightly, allowing fresh resin to flow between the printed layer and the vat’s base. The next layer is then cured, and the cycle repeats until the object is complete.

Different resin printing methods vary in how the UV light is generated and applied. These variations define distinct technologies, such as LCD, SLA, and DLP printing.

Which 3D Printing Method Is Right for You?

In general, FDM is the better option if you want a versatile printer capable of producing a wide range of objects. FDM printers are well suited for printing larger parts, functional components, and structural pieces that need to withstand mechanical stress, as well as simpler, lower-detail models.

On the other hand, resin printing excels at producing small, highly detailed objects. It is particularly suitable for prints that require fine detail, smooth surfaces, transparency, strength, or flexibility, and is commonly used in areas such as jewellery and miniature printing. While resin printers often involve a steeper learning curve and higher upfront costs, they remain accessible to dedicated hobbyists seeking high-quality results.