3D Printing Invention: Who Invented 3D Printing?

Who Invented 3D Printing?

Charles “Chuck” Hull is the person most commonly credited with inventing 3D printing because he invented stereolithography, secured the foundational U.S. patent for his system and helped turn the process into a commercial machine. That attribution is useful, but it is incomplete if it is taken to mean that no one had built objects layer by layer before Hull.

Japanese researcher Hideo Kodama had already developed a method for forming three-dimensional models by exposing a liquid photo-hardening polymer to ultraviolet light and stacking the resulting solid cross-sections. He applied for a Japanese patent in April 1980 and published an English-language paper describing working equipment and fabricated models in 1981. His work is one of the earliest clearly documented examples of the technical idea now associated with additive manufacturing.

A second complication appeared in France. Jean-Claude André, Alain Le Méhauté and Olivier de Witte filed a French patent application for a photopolymer-based model-making system on July 16, 1984. Hull filed his U.S. stereolithography application on August 8, 1984. The French filing therefore predates Hull’s U.S. filing by a few weeks, although the projects developed in different institutional settings and patent timing alone does not establish who first conceived every part of the idea.

The most accurate historical answer separates several kinds of “first.” Kodama provides an early documented working photopolymer process. The French team provides evidence of parallel invention in 1984. Hull created the stereolithography system that became commercially successful and established a direct line to the first generation of commercial 3D printers. Later inventors then created other processes that work on very different physical principles.

Hideo Kodama’s 1980–1981 Photopolymer Method

Kodama worked at the Nagoya Municipal Industrial Research Institute in Japan. His problem was tied to a new design practice: three-dimensional computer-aided design could describe a shape digitally, but viewing that shape on a screen did not produce a physical model that a designer could hold and inspect.

According to Nagoya University’s account of his work, Kodama saw photosensitive resin being used to make raised printing plates at an exhibition. Ultraviolet light hardened selected parts of the resin. He realized that repeating the hardening process in stacked layers could turn flat patterns into a three-dimensional form.

He began experimenting in early 1980. Nagoya University records that he produced a model of Himalayan terrain and then a house. The house was about 5 centimeters tall and consisted of 27 resin layers, each about 2 millimeters thick. Kodama later destroyed the original experimental apparatus, models and notes when he left research, so photographs and publications carry much of the surviving physical record.

His 1981 paper in Review of Scientific Instruments, “Automatic method for fabricating a three-dimensional plastic model with photo-hardening polymer,” describes the process in clear technical terms. Liquid photopolymer was exposed to ultraviolet radiation so that selected cross-sectional regions hardened. Repeating the exposure and stacking solidified cross-sections produced a three-dimensional model. Kodama reported that three types of equipment had been constructed and that solid models had been fabricated.

This matters because Kodama’s contribution was not merely a prediction that objects might someday be made in layers. His published work described equipment, operating conditions and completed physical models. It is therefore misleading to say that Hull’s 1983 stereolithography part was necessarily the first object ever made by a process that would now be recognized as 3D printing.

Why Kodama Did Not Establish the Commercial Industry

Kodama’s early patent history also shows why “first inventor” and “commercial founder” can diverge. Nagoya University states that he submitted his Japanese application in April 1980 but did not complete the later examination procedure needed for the application to become an enforceable granted patent. He also did not pursue foreign patent protection.

His research institute and manufacturers showed little interest in the rough early models. Kodama eventually left research and became a patent attorney. His work remained part of the historical record, but it did not lead directly to a product company or a commercial machine.

The French Patent Filed Before Hull’s U.S. Application

The 1984 French work is easy to miss because popular histories often move directly from Kodama to Hull. Patent record FR2567668A1, titled Device for producing a model of an industrial part, names Jean-Claude André, Alain Le Méhauté and Olivier de Witte as inventors. Its priority and filing date is July 16, 1984.

The patent describes a system involving a tank of liquid material, radiation and controlled scanning to form a model. The filing belongs to the same broad family of early liquid-photopolymer approaches that appeared as researchers tried to turn digital geometry into physical layers.

Hull’s U.S. application followed on August 8, 1984. The narrow difference between the filing dates is evidence of parallel development, not a reason to collapse the story into a race decided by three weeks. Patent dates establish documented legal priority for the material claimed in each application; they do not reveal every earlier experiment, private idea or engineering step that preceded filing.

Chuck Hull and the Invention of Stereolithography

Hull’s contribution is easier to connect to the modern industry. While working with ultraviolet-curable materials in California, he developed a practical system in which a controlled light source selectively hardened a liquid photopolymer according to cross-sectional data. Layer followed layer until the desired three-dimensional object emerged.

Hull produced an early stereolithography part in 1983. On August 8, 1984, he filed the U.S. application that became U.S. Patent 4,575,330, “Apparatus for production of three-dimensional objects by stereolithography.” The patent was issued on March 11, 1986.

The patent is historically useful because it shows what Hull was trying to solve. Conventional prototype production often required a designer to create a drawing and then rely on machining or other labor-intensive model-making methods. Revisions could require another round of physical fabrication. Hull’s system aimed to produce a three-dimensional object automatically from data describing its cross-sections.

The National Inventors Hall of Fame identifies Hull as the inventor of stereolithography and describes it as the first commercial rapid-prototyping technology commonly associated with 3D printing. This is a more precise claim than saying that Hull alone invented every process now placed under the 3D-printing label.

What Hull Added to the Earlier Photopolymer Idea

The lasting effect of Hull’s work came from combining several elements into a usable production system: controlled exposure of UV-sensitive resin, movement through successive layers, digital geometry, machine control and a path toward repeatable commercial hardware. The engineering problem was no longer only how to harden one resin layer. The system had to keep layer position, geometry and exposure coordinated through an entire build.

Hull also co-founded 3D Systems in 1986 to commercialize stereolithography. That move connected the laboratory process to customers who needed rapid prototypes, especially engineering and product-development teams.

How Early Stereolithography Worked

Stereolithography belongs to the process family now called vat photopolymerization. The essential material is a liquid resin formulated to solidify when it receives the appropriate light exposure.

1. A digital model is divided into cross-sections. Each cross-section represents one physical layer of the future object.
2. A controlled light source traces or exposes selected regions of liquid photopolymer. The exposed regions cure into solid material.
3. The build position changes by one layer increment. Fresh liquid resin becomes available at the working surface.
4. The next cross-section is cured and joined to the previous one. Repetition creates the full three-dimensional form.

The original SLA-1 architecture used a vat of UV-curable liquid, a UV light source, scanning optics, a movable platform and computer control. The important conceptual shift was that the machine could translate a digital three-dimensional design into a sequence of two-dimensional manufacturing operations and then reassemble those operations physically as a layered object.

This is why stereolithography is closely associated with the birth of 3D printing even though modern printers may use powder, thermoplastic filament, metal feedstock, droplets or binder rather than liquid resin.

The SLA-1 Turned Stereolithography Into a Commercial Machine

Hull’s patent was granted in 1986, but a granted patent is not the same thing as a product in use. The next marker is 1987, when 3D Systems commercialized its first-generation stereolithography system.

The Henry Ford preserves a 1987 SLA-1 described as the first commercially successful stereolithography machine and the first machine shipped by 3D Systems. Its recorded place of creation is Valencia, California. The museum’s artifact record provides rare object-level evidence for the point at which stereolithography moved from experimental development into commercial hardware.

ASME likewise recognizes the SLA-1 as an engineering landmark representing the first generation of commercially available 3D printers. The machine’s components included a photopolymer container, programmable UV source, scanning mirrors, movable elevator platform and computer control.

That distinction explains why 1987 is often used for the beginning of commercial 3D printing even though the experimental and patent record is older.

Why 1980, 1981, 1983, 1984, 1986 and 1987 All Appear in the History

Stereolithography Is Not the Same as Every Form of 3D Printing

The historical label can cause another problem. Hull invented stereolithography, but today 3D printing is an umbrella term for several process families that do not all use liquid resin or ultraviolet curing.

The current ISO/ASTM 52900:2021 vocabulary standard defines additive manufacturing around the successive addition of material to build physical three-dimensional geometry. ISO reviewed and confirmed that edition in 2025, so it remains the current reference standard for the basic terminology.

NIST’s additive-manufacturing technology pages illustrate how broad the field has become. Its process coverage includes powder bed fusion, directed energy deposition, material extrusion, vat photopolymerization, binder jetting and material jetting. Hull’s SLA belongs to vat photopolymerization. A desktop filament printer belongs to material extrusion. A laser-based powder system belongs to another process family entirely.

For invention history, this means that credit for stereolithography cannot automatically be treated as sole credit for every technology later grouped under additive manufacturing.

The Other Inventions That Expanded 3D Printing

Within a few years of Hull’s patent, researchers developed methods that replaced the liquid photopolymer vat with different materials and energy or deposition systems. These were not simple variations of one machine. They created separate technical lineages.

Carl Deckard and Selective Laser Sintering

Carl R. Deckard’s work at the University of Texas created a powder-based branch of additive manufacturing. His U.S. application for Method and apparatus for producing parts by selective sintering was filed on October 17, 1986, and U.S. Patent 4,863,538 was issued in 1989.

The process differs from SLA in its starting material. Rather than curing a liquid photopolymer, the system spreads powder and uses a directed energy source to consolidate selected regions according to the part geometry. Another powder layer is then added, and the cycle continues. Modern powder-bed systems include technologies descended from this general approach, although materials and machine architectures have developed far beyond the earliest apparatus.

Scott Crump and the Material-Extrusion Line

S. Scott Crump’s 1989 patent application describes creating three-dimensional objects by dispensing material in repeated layers from a controlled head. U.S. Patent 5,121,329, issued in 1992, explains a system in which the head and base move relative to one another along three axes while deposited material solidifies and bonds to earlier layers.

This lineage is especially important because it is much closer to the familiar desktop printer that feeds and deposits thermoplastic material. Fused Deposition Modeling became associated with Stratasys, while standards use the broader process-family term material extrusion.

The MIT 3DP Process and the Name “3D Printing”

A team at the Massachusetts Institute of Technology—Emanuel Sachs, John S. Haggerty, Michael J. Cima and Paul A. Williams—filed a U.S. patent application on December 8, 1989, titled Three-dimensional printing techniques. The patent, issued in 1993 as U.S. Patent 5,204,055, describes spreading a powder layer and selectively depositing binder so that chosen regions become bonded. Repeating the operation creates the component.

The terminology is historically revealing. Earlier systems were commonly discussed as stereolithography or rapid prototyping rather than under one universal “3D printing” label. MIT later described its machine as one of the first practical 3-D printers and the first to be called by that name. Over time, 3D printing expanded in popular use from a process-specific phrase into a general label covering technologies that had originated under different names.

What 3D Printing Changed in Prototype Making

The early inventors were solving a practical gap between digital design and physical evaluation. Computer-aided design made it possible to alter geometry on a screen, but engineering teams still needed physical prototypes to inspect fit, shape and design decisions.

Traditional prototype routes could involve skilled machining, manual model-making, patterns or molds. Some methods made sense for production volumes but were costly or slow when a designer needed one revised model. Hull’s patent explicitly discusses the time and effort involved in producing and revising plastic prototypes, while Crump’s later patent similarly contrasts automated layered fabrication with machining and molding routes.

Layer-based fabrication changed the relationship between design and making. Once a machine could interpret a digital model as successive cross-sections, the geometry itself directed much of the manufacturing sequence. A new version of the design did not necessarily require a new mold or a machinist to recreate the shape from scratch.

This is why the earliest commercial systems were strongly associated with rapid prototyping. The first goal was not to replace every factory process. It was to shorten the path from a computer model to a physical object that designers and engineers could examine.

Why “The First 3D Printer” Also Depends on the Definition

The phrase first 3D printer can refer to at least three different things.

• Early experimental apparatus: Kodama built equipment and fabricated layered photopolymer models before Hull’s stereolithography patent filing.
• Hull’s stereolithography prototype line: Hull produced an early SLA part in 1983 and then filed the patent application that became the core U.S. stereolithography patent.
• Commercial machine: the 1987 SLA-1 provides strong museum evidence for the first commercially successful stereolithography machine and the first machine shipped by 3D Systems.

Calling the SLA-1 the first commercial 3D printer is therefore much safer than calling it the first device ever to create a three-dimensional object layer by layer. The latter wording erases the earlier Kodama record.

The Most Accurate Attribution

If one person must be named in response to “Who invented 3D printing?”, Chuck Hull is the strongest answer for the invention and commercialization of stereolithography and for the direct origin of the commercial 3D-printing industry. His work produced a patented, repeatable system that became marketable hardware.

For the earliest documented photopolymer layer-fabrication work, however, Hideo Kodama belongs earlier in the record. His 1980 patent application and 1981 publication document working equipment and fabricated models before Hull’s SLA development. The French filing by André, Le Méhauté and de Witte shows that related photopolymer methods were also developing independently in Europe by 1984.

Modern 3D printing then became broader than any one of those systems. Deckard’s powder-based selective sintering, Crump’s material-deposition process and MIT’s binder-on-powder 3DP process established separate branches of additive manufacturing. The invention is best understood as a sequence of documented technical advances rather than a single date attached to a single machine.