What Is DLP 3D Printing? DLP vs SLA vs LCD Explained

Quick answer: DLP technology (Digital Light Processing) is a type of resin 3D printing that uses a projector to cast the full image of an entire layer onto a vat of liquid resin at once. The resin hardens wherever it is exposed to light. According to CT3D’s technical data, DLP prints layers of 25–100 microns with tolerances of about ±0.03–0.08 mm. Unlike SLA, which traces each line with a laser, DLP “flashes” the whole layer in one go, so it is fast for small parts and produces crisp detail.

This article is an introduction for beginners: what DLP is, how it works, and why it is so often mentioned alongside SLA and LCD. I have deliberately kept things simple. The full technical comparison (resolution, speed, build size, cost) is in our in-depth article SLA vs DLP vs LCD: what’s the difference. If you are ready to order, see also custom resin printing – materials and prices.

What Is DLP Technology? Explained with a Projector

Think of the projector in a meeting room. It throws an entire slide onto the wall at once rather than writing it letter by letter. A DLP printer uses the same idea. Inside the machine is a UV light projector. Each layer of the model is a black-and-white “slide”: the white areas are where the resin should harden, and the black areas stay liquid.

The light shines through the transparent bottom of the resin vat. Resin in the illuminated areas solidifies into a thin layer that sticks to the build platform. The platform lifts slightly, and the projector shows the next “slide”. This repeats until the part is complete.

The heart of a DLP projector is the DMD chip (Digital Micromirror Device): a chip with hundreds of thousands to millions of microscopic mirrors. Each mirror tilts back and forth to switch a point of light on or off, and each point of light corresponds to one pixel in the printed layer.

Basic DLP Vocabulary

• Photopolymer resin: a liquid plastic that hardens under UV light.
• DMD chip: the micromirror chip that controls the light in a DLP projector.
• Pixel / voxel: a pixel is a point on a flat image; a voxel is a “3D pixel” that also has the layer thickness.
• Exposure time: the number of seconds each layer is illuminated. Too short and the layer does not cure; too long and fine details bloat.
• Build platform: where the part attaches and is gradually lifted.

How Does a DLP Printer Work?

1. File preparation: the software slices the model into layers and turns each layer into a black-and-white image. The engineer tilts the part and adds supports.
2. Exposing the first layers: the first layers get a longer exposure so they bond firmly to the build platform.
3. Exposing each layer: every layer is illuminated once for a few seconds. Layer time stays almost the same whether there is one part or many on the platform.
4. Peeling and lifting: the platform peels the freshly cured layer off the bottom of the vat, and fresh resin flows in.
5. Post-processing: wash off excess resin, UV cure until fully hard, cut supports, sand and paint if needed. Details are in resin print post-processing.

The nice thing about DLP: because it exposes a whole layer at once, filling the build platform with many small parts barely increases the time per layer. That is why DLP is popular in dentistry and jewelry, where many small parts are printed at the same time.

How Is DLP Different from SLA and LCD? A Beginner’s Summary

These three technologies are close siblings: they all use resin and UV light. The main difference is how the light reaches the resin. The table below covers only the key points. A detailed analysis of each criterion is in SLA vs DLP vs LCD: what’s the difference.

Technology	Light source	How a layer is formed	Easy-to-remember analogy
SLA	UV laser beam	Traces line by line until the layer is filled	Coloring in a shape with a pen
DLP	UV projector with a DMD mirror chip	Exposes the whole layer at once	A slide projector
LCD (MSLA)	UV LED array behind an LCD screen	The screen masks the light, revealing the shape of the layer	A flashlight shining through a paper stencil

Source: CT3D technical documentation and general knowledge of resin 3D printing.

For beginners, all three deliver smoother surfaces and better detail than FDM. Choosing the machine is the print shop’s job. You just need to tell us what the part is for, how big it is and how good it needs to look.

Advantages and Limitations of DLP Technology

Advantages

• Crisp detail: typical tolerance of ±0.03–0.08 mm according to CT3D data, well suited to small features.
• Fast for small parts and batch printing: each layer is exposed only once.
• Smooth surface: layer lines are very faint, and parts take paint beautifully.
• Consistent: ideal for repeatedly printing identical parts such as dental models and ring patterns.

Limitations

• Build size is usually small: the resolution is spread across the projected area, so enlarging the projection makes each pixel larger.
• Pixel stepping may be visible on curved edges if the resolution is low relative to the part size.
• Resin and post-processing costs are similar to other resin technologies and higher than FDM.
• Standard resin is more brittle than FDM plastics; load-bearing parts require specialty resins.

What Is DLP Used For in Practice?

Dentistry

Dental models, aligner trays and impression trays. Labs need to print many small, accurate, repeatable parts. See also dental and medical resin 3D printing.

Jewelry

Ring and pendant patterns and fine filigree printed in castable resin, then cast in metal. Our article castable resin patterns for jewelry explains the process.

Figures and Small Models

Characters a few centimeters tall with detailed faces, fingers and small weapons. The smooth surface makes painting quick and attractive.

Small Technical Parts

Connectors, sensor housings and mini gears for fit checks. Remember to choose a tough resin if the part has to carry loads.

For large parts such as 1 m tall statues, print shops usually use large-format SLA. CT3D offers a resin build volume of up to 800 × 800 × 500 mm and has printed a 1 m tall Catholic statue in SLA.

When to Choose DLP and When to Choose Another Technology

• Small parts, extreme detail, many identical copies: DLP is an excellent fit.
• Large parts that should be one piece with a smooth surface: large-format SLA is usually better.
• Cheap, large, tough parts where smoothness does not matter: FDM is the economical choice. See FDM vs resin 3D printing.
• Load-bearing nylon parts and low-volume production: consider MJF/SLS.

You do not have to decide on your own. Send your file and describe what it is for, and CT3D engineers will recommend the right technology and explain why.

Common Problems in DLP Resin Printing

• Part does not stick to the platform: insufficient first-layer exposure or an unleveled platform.
• Bloated details, small holes closing up: exposure time too long.
• Layer tearing or separation: large cross-sections, high peel forces, or resin that is too cold.
• Cracking after curing: thick solid parts or excessive UV curing.

In the CT3D workshop, resin is kept at around 25–28 °C and parts are tilted 20–45 degrees, which keeps our failure rate below 5%. The full list of problems and fixes is in common resin 3D printing problems.

How Is DLP Resin Printing Priced?

The price depends on resin volume, resin type, part height, the number of parts per build plate and the finish level. CT3D quotes per file. For reference, the 2026 Ho Chi Minh City market range for standard resin (not CT3D’s price) is about 150,000–400,000 VND (≈ US$6–15) for parts under 5 cm; these figures are indicative. Specialty resins such as tough, clear and heat-resistant grades carry a surcharge. The general price list is in How much does 3D printing cost?

Frequently Asked Questions

What does DLP stand for?

DLP stands for Digital Light Processing. It uses a projector with a micromirror chip to project the image of each layer onto the resin.

Which is more accurate, DLP or SLA?

Both are very accurate. According to CT3D data, DLP achieves about ±0.03–0.08 mm and SLA about ±0.05–0.1 mm. Actual results also depend on the machine, the resin and the part geometry.

Can DLP print large parts?

DLP build volumes are usually small. Large parts typically use large-format SLA or are split into sections and joined.

Do DLP prints need post-processing?

Yes. Excess resin must be washed off, the part UV cured and the supports cut. Painting is optional.

How is DLP different from LCD?

DLP uses a projector, while LCD uses a screen to mask the light. Both expose an entire layer at once. For details, see our article SLA vs DLP vs LCD.

Real Footage from the CT3D Workshop

Watch Ultra-smooth SLA resin 3D printing workshop, produced by CT3D, to get a clearer picture of the process and the quality of the finished parts. More videos are available on our YouTube channel Che Tao Vlog – CT3D.

Contact CT3D – Send Your File, Get a Fast Quote

Whether you have a 3D file, a 2D drawing, photos or just an idea, you can send it to CT3D. Our engineers will check the file, recommend the right technology and material, and send you a quote with a delivery lead time.

• Email: [email protected] – [email protected]
• Hotline / Zalo: +84 975 008 728 (Mr. Thai) – +84 985 936 728 (Mr. Dang), or use our contact form
• Head office: Binh Duong.
• Workshops in Ho Chi Minh City: Linh Trung (Thu Duc), Tam Binh (Thu Duc), former District 6.
• Other workshops and drop-off points: Can Tho, Da Nang, Bien Hoa, Ba Ria – Vung Tau, Hanoi, Hai Duong, Hai Phong. Nationwide delivery.
• Website: ct3dgroup.com – in3d.edu.vn

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