What is Additive Manufacturing (3D Printing)?
Additive manufacturing, commonly known as 3D printing, is a cutting-edge manufacturing process where objects are created by depositing material layer by layer, directly from a digital model. Unlike traditional subtractive methods that involve cutting or milling away from a solid block, additive manufacturing builds up a product precisely and efficiently—reducing waste and allowing for intricate designs. The concept emerged in the 1980s, with the first 3D printer developed by Charles Hull in 1983 using a technology called stereolithography (SLA). Since then, the field has rapidly evolved, giving rise to a range of printing methods capable of producing parts in plastics, metals, ceramics, and even biological materials. Today, additive manufacturing is reshaping industries across aerospace, healthcare, education, architecture, and consumer products, offering a flexible, localised, and sustainable approach to design and production.
It empowers individuals, startups, and industries to innovate faster and manufacture smarter. The future of making is no longer limited by complexity, but only by imagination.
How Does 3D Printing Work?
At its core, 3D printing is a digital-to-physical process that begins with a virtual design. This design is created using specialised software known as CAD (Computer-Aided Design), or it can be captured using a 3D scanner. Once the design is ready, it is converted into a printable file format—most commonly STL or OBJ—and processed through a slicing program. The slicer divides the model into hundreds or even thousands of ultra-thin horizontal layers and generates the machine instructions that tell the printer exactly how to build each layer.
Depending on the type of 3D printing technology, the printer then begins building the object layer by layer. In FDM (Fused Deposition Modelling), for example, melted thermoplastic filament is extruded through a heated nozzle. In SLA (Stereolithography), a laser selectively cures a liquid resin. Other technologies use powdered materials, binding agents, or even metal melting techniques like laser sintering.
This additive approach allows for an extraordinary level of freedom in design. Complex internal structures, lightweight lattices, and intricate geometries that are impossible with traditional manufacturing can be printed with ease. It also results in minimal material waste since only the required amount of material is deposited. Whether it's a simple prototype or a fully functional end-use product, 3D printing delivers precision, efficiency, and adaptability unmatched by conventional production methods.
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Types of 3D Printing Technologies
The History and Evolution of 3D Printing Technologies
The story of 3D printing—also known as additive manufacturing—is one of groundbreaking innovation and continuous evolution. Since its inception in the early 1980s, this transformative technology has redefined the way we design, prototype, and manufacture products across a wide range of industries. From humble beginnings as a tool for rapid prototyping, 3D printing has matured into a powerful suite of advanced manufacturing methods capable of producing everything from medical implants and aerospace components to full-scale houses and consumer goods.
The journey began with the invention of stereolithography (SLA) in 1983 by American engineer Charles Hull, who developed the first process capable of turning digital designs into physical objects using light-sensitive resin. This marked the beginning of the additive manufacturing revolution. As the decade progressed, researchers and engineers around the world began to experiment with new techniques and materials. In the 1990s, Fused Deposition Modelling (FDM) and Selective Laser Sintering (SLS) emerged, opening the door to more robust and accessible 3D printing systems. These technologies brought affordability and practicality to a growing range of applications in engineering, product development, and education.
Throughout the 2000s and 2010s, the field expanded rapidly, with the introduction of metal 3D printing technologies such as Selective Laser Melting (SLM) and Direct Metal Laser Sintering (DMLS), which enabled the production of high-performance parts for use in demanding sectors like aerospace, automotive, and healthcare. Simultaneously, innovations like Digital Light Processing (DLP) and Material Jetting brought new levels of precision and surface finish, making them ideal for dentistry, jewellery, and visual prototypes.
Recent developments have pushed the boundaries of scale and material diversity. Technologies such as Binder Jetting, Multi Jet Fusion (MJF) by HP, and Concrete 3D printing (Contour Crafting) have demonstrated how 3D printing can be applied to mass production, civil engineering, and even sustainable housing. These newer systems have improved speed, part strength, and cost-efficiency—closing the gap between prototype and production-ready manufacturing.
Today, 3D printing is no longer confined to research labs or specialised factories. It is a widely adopted manufacturing solution, integrated into educational institutions, hospitals, construction sites, and consumer markets. Each technology has its own unique strengths, suited to different materials, production volumes, and end-use applications. Understanding the origin and evolution of these technologies is key to appreciating their potential and choosing the right process for the right job.
1. Stereolithography (SLA)
Invented: 1983 by Charles Hull (USA)
Historical significance: The first ever 3D printing technology
Stereolithography was the world's first commercialised 3D printing process. Invented by Charles Hull in 1983, SLA uses a UV laser to cure liquid resin into hardened plastic, one layer at a time. Hull went on to found 3D Systems Corporation, which still manufactures SLA machines today. SLA revolutionised rapid prototyping, allowing product designers and engineers to create accurate visual and functional prototypes much faster than traditional methods.
Today, SLA is widely used in dentistry, medical modelling, and jewellery, due to its ability to produce intricate, high-resolution parts.
2. Fused Deposition Modelling (FDM) / Fused Filament Fabrication (FFF)
Invented: Early 1990s by Scott Crump, co-founder of Stratasys
Historical significance: Made 3D printing more accessible
FDM, patented by Stratasys in 1989, was the first 3D printing technology to use melted thermoplastic filament extruded through a heated nozzle. It became the most widely used method due to its simplicity, low cost, and scalability. When the patents expired in the 2000s, open-source and desktop FDM printers (like the MakerBot and Prusa) exploded in popularity.
Today, FDM is dominant in education, consumer markets, and engineering prototyping, with applications ranging from custom tools to pro
3. Selective Laser Sintering (SLS)
Invented: Mid-1980s by Dr Carl Deckard and Dr Joe Beaman at the University of Texas
Historical significance: Enabled functional, durable plastic parts
SLS was developed around the same time as SLA but took a different approach: using a laser to fuse powdered nylon or other thermoplastics without the need for support structures. This made it ideal for producing complex, interlocking parts and functional prototypes.
Today, SLS is commonly used in aerospace, automotive, and industrial design, thanks to its ability to create strong, precise components suitable for real-world use.
4. Digital Light Processing (DLP)
Invented: Developed commercially in the late 1990s based on Texas Instruments’ DLP projector technology
Historical significance: A faster alternative to SLA
DLP works similarly to SLA but uses a digital projector instead of a laser to cure resin all at once per layer. This makes the process faster and often more affordable. As projector technology improved, DLP printers became compact and precise, entering the consumer and professional market.
Today, DLP is used in dental labs, jewellery design, and miniature figurine production, where speed and surface detail are critical.
5. Selective Laser Melting (SLM) / Direct Metal Laser Sintering (DMLS)
Invented: Early 1990s in Germany by Dr Wilhelm Meiners and Dr Konrad Wissenbach (SLM)
Historical significance: Made metal 3D printing commercially viable
SLM and DMLS are powder bed fusion technologies developed to build metal parts layer by layer. These processes allowed industries to create fully dense metal components with complex geometries impossible through traditional manufacturing.
Today, they are essential in aerospace, medical implants, and high-performance automotive applications where lightweight, custom metal parts are needed.
6. Binder Jetting
Invented: 1993 at MIT by Ely Sachs and Mike Cima
Historical significance: Introduced multi-material and full-colour printing
Binder jetting uses a printhead to deposit a liquid binding agent onto a powder bed (sand, metal, or ceramic), layer by layer. Initially developed for academic research, the technology was later commercialised for industrial applications like sand casting moulds and metal parts.
Today, it is used in construction (concrete printing), decorative ceramics, and mass-customised components.
7. Multi Jet Fusion (MJF)
Invented: 2016 by HP
Historical significance: Improved speed and part strength in polymer printing
Developed by Hewlett-Packard, MJF combines inkjet arrays with heat to fuse polymer powder. It’s significantly faster than SLS and can produce mechanical-grade parts with superior surface finishes.
Today, MJF is widely adopted in mechanical engineering, consumer electronics, and healthcare for functional parts, including prosthetics and orthopaedic gear.
8. Material Jetting
Invented: Commercialised in the early 2000s by Objet (now Stratasys)
Historical significance: Enabled multi-material and multi-colour printing
Material jetting uses printheads to jet photopolymer droplets, which are then cured with UV light. The technology allows printing multiple materials and colours in one build.
Today, material jetting is used in realistic medical models, product design mock-ups, and custom eyewear, providing highly detailed and accurate representations of final products.
8. Material Jetting
Invented: Commercialised in the early 2000s by Objet (now Stratasys)
Historical significance: Enabled multi-material and multi-colour printing
Material jetting uses printheads to jet photopolymer droplets, which are then cured with UV light. The technology allows printing multiple materials and colours in one build.
Today, material jetting is used in realistic medical models, product design mock-ups, and custom eyewear, providing highly detailed and accurate representations of final products.
9. Laminated Object Manufacturing (LOM)
Invented: Late 1980s by Helisys Inc.
Historical significance: One of the earliest large-format 3D printing techniques
LOM works by laminating layers of material (usually paper or plastic) and cutting them into shape with a laser or blade. Although less precise, it was cost-effective for large architectural or engineering models.
Today, LOM is used primarily in architectural design and educational displays, offering fast and affordable visual models.
10. Concrete 3D Printing / Contour Crafting
Invented: Late 1990s by Dr Behrokh Khoshnevis at the University of Southern California
Historical significance: Pioneered large-scale construction printing
Contour crafting uses a robotic arm to extrude concrete and build walls layer by layer. This method gained attention for its potential to build houses quickly, especially in disaster zones or for affordable housing projects.
Today, it is being used in construction, urban development, and military base infrastructure, with full-scale 3D-printed homes and bridges already built in several countries.