How DLP Printing Works? | The Definitive Guide 2022

how dlp printing works

What is DLP Printing?

Before talking about how DLP printing works in detail, first, understand what it is actually. Digital light processing is a modern 3D printing technique under the vat polymerization method known for using liquid photopolymer resin and solid components using light beams.

To understand DLP 3D printing method properly, we need to first know about vat polymerization and DLP’s closest competitor, SLA or stereolithography. Both techniques use a light source and liquid resin for production, but the key difference lies in how they both use it.

SLA consists of a build platform, an elevator that moves it up and down, a resin-filled tank, a light source, and galvanometers. SLA 3D printing starts with the build platform lowering itself and contacting the resin-filled tank with only one layer of height left between the bottom of the tank. Now the galvanometers come into the play.

Galvanomteres are essential for guiding the laser beam to the bottom of the tank. The G-code helps galvanometers steer the laser beam in a path representing one layer of a certain part. The laser comes in contact with the liquid resin, it cures it up to a point, will a single layer is complete, now the build platform moves up one notch, and the process will be repeated till the component is completed.

How DLP Printing works? 

DLP machine

Source -

Let’s get to the main part of the post; let’s understand how DLP 3D printing actually occurs.

DLP is often called a successor of SLA and for the right reason, as it uses a light source to cure resin rather than a laser beam.

  1. In a DLP 3D printer, the light source is developed regarding the digital light projection screen. The screen makes DLP much faster than SLA. Here’s why.
  2. With DLP printing, it’s easier and more specific as the digital projector screen flashes an image of a layer all at the time! Curing all points of a layer simultaneously. On the other hand, with SLA, the laser has to cure the resin independently in a “point to point” fashion. That is a crucial difference-making DLP faster as it takes less time to cure a single layer.
  3. DLP printing is a digital technology, so the projected 2D image, composed of pixel transforms into voxels when the 2D image is translated into a 3D image.
  4. The LED screen is the light source for every 3D printer, meaning a digital micrometer device (DMD). A DMD comprises hundreds of thousands, if not millions, of micromirrors that navigate the light to create a layer’s pattern onto the bottom of the resin tank.
  5. The number of micromirrors in a DMD device greatly affects the quality and resolution of the printed part.

Apart from that, DLP 3D printers have a shallower or trifling vat of resin, which leads to less wastage of resin.

Interesting Read – How is Plastic Made? A Simple and Detailed Explanation.

Post-Processing – 

The post-processing is fairly straightforward. If you have used a support structure, they need to be removed by placing the part in a bath of isopropanol or a similar solvent. The part should be left for about 30 minutes to 1 hour for parts to dissolve.

Advantages and Disadvantages of DLP 3D printing – 

dlp advantages and disadvantages


  1. Producing complex and intricate designs is easy. More accurate than FDM and SLS 
  2. Faster processing time. Printing with resin is significantly faster than printing with filaments. That’s why fast-paced industries prefer resin-based printing. It’s faster than SLA most of the time.
  3. A shallower resin vat makes the process inexpensive and also more environment friendly compared to SLA and SLS.


  1. Its overall cost is more than FDM – resins are more expensive than filaments, and the resin tank also needs to be replaced regularly, which adds up costs.
  2. Poor UV resistance – prolonged exposure to the sun will degrade the parts.
  3. Poor mechanical properties – Parts will break easily and are at risk of deteriorating over time.

Applications –

DLP applications

  • Medical 
  • Jewelry
  • Gifting 
  • Dentistry
  • Bio-compostable 

1. Medical Applications:

Medical is one of the largest consumers of DLP printing products, thanks to accuracy and precision. It is mostly utilized for producing precision medical devices, medical models, and precision medical appliances.

Common applications include bones, dental models, muscle models, devices and appliances for the hearing aid industry, DNA samples, etc.

2. Jewelry:

Jewelry is one of the earliest and most basic applications for digital light processing. Jewelers worldwide are using this technology to develop unique and stylish jewelry designs at a considerably lower cost than traditional manufacturing methods.

Creating wax pieces of a design eliminates a crucial step of creating a mold, thereby saving a lot of time and resources.

The market has come a long way in terms of adoption, and small and micro-sized businesses are also taking advantage by directly printing their design from service bureaus.

3. Gifting:

The gifting industry is always evolving with new trends, and thus keeping up with these trends can become a challenge. That’s when DLP comes to the rescue, as it’s fast and accurate. 3D printed models can also help keep up with industry trends by rapid prototyping, becoming a tedious task in other traditional manufacturing methods.

4. Dentistry: 

Dentists are also quite thankful for digital light processing technology as it makes it easier to printing surgical guides, crowns & bridges, and orthodontic devices. These devices and models used to take weeks and even months in some cases to make, and still, the suitability with the patient was not perfect.

However, now the models made from DLP printers are as accurate as 25 microns and even less. Such precision will keep the demand for DLP printing intact, and more complex innovations are awaited from the industry.

5. Bio-compatible:

If dentists are implanting dental models in a patient, they need to consider that these models need to be bio-compatible. When surgical guides or aligners are implanted into a patient’s mouth, the saliva can come in contact with the extraneous part. Thus it is compulsory to use only that resin to make the parts that won’t cause any harm to the patient.

For that reason, scientists have developed bio-compatible resin which doesn’t affect the patient negatively while carrying out the procedure.

Engaging Read – What is 3D Printing? | Types of 3D Printing | Applications of 3D Printing | Advantages & Disadvantages

FAQs –

1. What are the different types of 3D printing methods?

Ans. There are several types of 3D printing methods used for various purposes. The most popular ones are:-

  1. Stereolithography (SLA)
  2. Fused Deposition Modeling (FDM)
  3. Selective Laser Sintering (SLS)
  4. Digital Light Process (DLP)
  5. Direct Metal Laser Sintering (DMLS)
  6. PolyJet
  7. Electron Beam Melting (EBM)

2. What is DLP resin?

Ans. As mentioned earlier too, digital light processing is part of vat polymerization methods. All vat polymerization methods use some photopolymer resin that has the ability to solidify itself while coming in contact with light. The two most sought-after VAT polymerization techniques are SLA and DLP.

3. What can I 3D print at home?

Ans. There are several of these which can be easily 3D printed at home. The most common and easy applications are:-

  1. Pencil
  2. Planters
  3. Measuring Cube
  4. Pencil Holder
  5. Flexi Rex
  6. Faucet Water Saver
  7. Cable Holder
  8. Cutleries

And a lot more…

4. What software should I for 3D printing?

Ans. There is several trustworthy software that can be used for 3D printing. However, the best ones are:-

  1. Autodesk Fusion 360
  2. Autodesk AutoCAD
  3. Ultimaker Cura
  4. TinkerCAD
  5. MeshLab.
  6. Solidworks
  7. FreeCAD

5. Why is FDM suitable for PLA printing?

Ans. PLA is good at enduring heat, chemical, and mechanical stresses, making it perfect for producing newer prototypes. Additionally, as FDM is used for creating detailed objects, its applications are high in fit and form segment.

Final Thoughts – 

That was all I had to say about how DLP printing works and all related attributes. Digital light processing technology can be extremely beneficial for a manufacturer if utilized properly.

Kindly share your reviews in the comment box.

Have a lovely week 🙂

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