SLA Vs DLP: Know The Actual Difference Between Them

Resin is one of the most common materials used in 3D printing technology. Many mechanisms have been created using this substance as their backbone.

3D printing has revolutionized the way we view technology. It has transformed the scientific fantasy of our forefathers to a tangible reality.

SLA and DLP are two of the most widely used 3D printing technologies that involve resin.

These terms may seem unfamiliar to you. Let’s discuss them in detail and highlight the pros and cons of SLA or DLP. These factors will help you decide which one is better.

What is SLA?

SLA stands for stereolithography. It is a term that refers to 3D printing. It is well-known for its precision and smoothness, as well as other benefits. It is a popular choice in additive manufacturing.

High-powered lasers are used to harden the liquid resin and create 3D structures. The lasers are used to deliver light through the lasers to photopolymerize in a specific area of the resin. Each layer forms as the laser moves across a resin container.

Since the 1980s, this process transforms photosensitive liquids into solid materials. It was one of the first methods that 3D printing became possible.

There are two variations of this method – one uses the laser from above and the other one points the laser from below.

SLA has many advantages


SLA is known for 3D printing with more precision than other processes. This process can provide more detailed information on the subject or design than many of its competitors. This is due to the fact that it creates highly isotropic components.

Prototypes with high quality

SLA can be used to present prototypes of better quality to clients if you are looking to improve your 3D printing business.

This method can produce fine details, such as sharp corners or thin walls. It supports printing layers with a minimum thickness of 25 μm and a size of 50 to 250 μm. Its features allow you to create complex shapes easily.

Tightest Dimensional Tolerances

3D printing is known for having greater deviations than other technologies. Comparable to CNC machining This additive technology is also known as injection molding. It has a minimum tolerance of 0.1mm.

SLA provides the most precise options in this instance by providing 0.127mm tolerance in first inch and 0.0.05mm in every inch thereafter. This is just one of many factors that contributes to the high accuracy of SLA prints.

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Smooth Surfaces

SLA excels at smoothness, as well as the other features mentioned. SLA printing often produces a surface that is comparable to those produced by traditional methods like injection molding or machining. SLA printing is able to achieve a flawless finish that is unmatched by other methods.

High Build Volumes

SLA 3D printers can produce high build volumes without compromising precision. SLA 3D printing is highly adaptable by default. It does not depend on the printer resolution to determine its build volume. You can print large quantities of small or large parts while still maintaining high resolution and details.

SLA’s disadvantages

Tricky Support Structures

It can be difficult to use and maintain support structures when working with SLA. These structures are often required for steep slopes and overhangs when you are designing the main design. These parts are more susceptible to collapsing in the curing and print stages of SLA.

Limited Color Options

SLA 3D printing is not for you if you want to be able to print in a variety of colors and materials. It only offers the most basic shades, such as black, white, grey, and transparent. This method that involves resins does not offer a wide range of design options.

What is DLP?

Digital Light Processing, also known as DLP, is another form 3D printing with resins. It can be classified as one type of SLA. vat polymerization technology Where the liquid photopolymer has been cured or solidified by light. However, DLP uses a different source of light – projector screen!

The screen of the digital light projector flashes each layer in pixels. It is later transformed into 3D where the pixels are turned into voxels – units of a 3D grid. The DLP-compatible 3D printers have an additional light source, which is LED screens.

DMD, also known as digital micromirror or DMD, is an important component in lighting DLP methods. Because of the millions of rotating micromirrors that are contained within DMDs, this device is often called the heartbeat of DLP chipsets. They direct the light and create the desired layer pattern.

DLP has many advantages

Fast Printing

DLP is a popular printing method that prints extremely fast. DLP prints from layer to layer, instead of just going from one point to another. It prints all points of a layer at once. This increases efficiency and can be used to satisfy more clients in the same time.


Resin’s main material does not have much strength. It is a viscous, solid substance that can easily be molded in many ways. DLP is one of the few methods to create strong structures even using resin. It can now offer strength that is equal or higher than injection molding.

Lots Of Colors

DLP’s impressive range of colors is another reason why so many people trust it for their 3D projects. You can use DLP to create 3D model in many different shades, using resins that contain CMYK pigments.

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Low Maintenance

You don’t have to worry too much about maintaining the DLP machines. Their architecture or mechanism are not as complicated than other 3D printing methods.

As a result, they don’t usually require professional supervision. You can easily find a new part if a component starts to fail or becomes damaged.


DLP printers can be more affordable because of their simplicity and easy to use procedures. Each printer is approximately four to six times less expensive than other 3D printers. This printer is highly sought after by 3D printing enthusiasts with tight budgets.

DLP’s disadvantages

Low Accuracy

DLP is full of colors and diverse designs. But there’s a catch.

It can’t provide enough precision to the details in your 3D structures. You might see details without the sharp features that you originally wanted.

You may not notice many of the subtleties you intended to highlight.

Boxy Finish

If your project requires a smooth finish, DLP is not the right choice. This process uses voxels rather than pixels. Voxels are rectangular 3D units Your design may have a prominent shape that is visible on the curved areas. You can resolve this problem by sanding your print properly after it has been printed.

Comparing DLP and SLA


SLA and DLP are the stars of 3D printing with resins or vat polymerization.

Stereolithography is primarily used to create medical models, prototyping and computer hardware. Since the 1990s, it has been able to print 3D models for human anatomy. SLA is used by businesses to create prototypes for their future products and allow them to be evaluated before they are released to the public.

DLP can also help to create certain medical models, such as the dental parts of patients or the ear shells for hearing devices. It takes only a few hours. It is used by jewelry makers to create colorful rings, bracelets and earrings. It can also be used to print midsoles by shoe manufacturers.

Light Source

Their light source is the key difference between their work processes. SLA uses a UV beam laser to print the details on every point of your design. On DLP, on other hand, uses the UV light of a digital light projector for each layer of the 3-D model.

Increase Volume

The distance between the projectors and the optical windows determines the build volume of DLP3D printing. You can know the number of voxels or pixels from the projector’s resolution. These pixels shrink as the projector is moved closer to the optical windows. The resolution increases and the build area decreases.

A single HD 4K projector can be used to increase the build volume of DLP projects. You can also stack multiple projectors side to side. However, this increases the cost of maintenance.

In contrast, SLA can readily offer impressive scalability since its build volume does not depend on the print’s resolution. The 3D printed model can be made in any size and resolution. SLA can be used to print small parts with intricate details and large parts of high resolution.

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SLA is capable to produce 3D models with intricate details with perfection. Because it prints each point individually, unlike DLP, the process is more efficient than printing the entire layer at once. Every bit of the design is brought to life with precision and far more accuracy than DLP.


SLA is a better choice for those who work on projects that require a smooth surface. DLP has this problem because the smallest unit of its entire system is rectangular. The curved parts have a boxy, rather than smooth surface.


The resolution of DLP prints depends on the pixel size which in turn relies on the projector resolution and the projector’s distance from the optical window. This value is usually fixed and can range from 35 to 100 millimeters. On the other hand, SLA depends on the laser beam’s spot size and its increments used for controlling.


DLP prints the 3D model much faster than SLA. DLP’s high speed printing is due to the mechanism. DLP prints each layer at once, while SLA prints only one layer at time. DLP prints in a significantly shorter time than SLA.


DLP is the best choice for commercial 3D printing, as it offers greater consistency and reliability. These printers usually have fewer moving parts that SLA printers. They are therefore less likely to fail while printing.


DLP machines have a simple structure. As a result, maintaining it doesn’t create too much trouble either. SLA machines require you to be more careful, as they have a complex structure and require precise calibration.


DLP printers are typically cheaper than SLA due their simpler structure. Common printers that support DLP printing are usually around a thousand dollars. SLA machines are usually three to four times more expensive than DLP.

Bottom Line – Which One is For You?

As you can see, there are no clear winners in this SLA/DLP debate. Both offer very strong features for 3D printer enthusiasts.

SLA can deliver greater precision, smoothness, build volumes, and more precise results. On DLP, on the other hand, can offer a wider range colors, faster speeds, and a more affordable price.

The type of project you are working on and your preferences will determine the best 3D printer. You can choose one based on your specific needs.

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