Resin 3D Printing Process: A Comparison of SLA and DLP!

2026-03-10

SLA vs. DLP 3D Printing Resin Technologies: A Complete Comparison

This article focuses on SLA and DLP 3D printing resin technologies, identifying their core characteristics to establish a thorough comparison between the two processes. While the two technologies share many similarities, they also have distinct differences. How do these technologies work? What materials can be used? Who are the leading manufacturers? We provide a systematic introduction and comparison below.

SLA and DLP Technologies

Despite their differences, SLA and DLP 3D printing processes have key similarities. Both expose liquid photopolymers to a light source, and both use a resin vat to produce small, highly detailed models. They are compatible with rigid, flexible, and composite materials (such as glass-filled or ceramic-filled resins).

It should be noted that printed parts are relatively fragile, prone to degradation when exposed to sunlight, and may experience warping.

Both SLA and DLP use liquid resin.

Stereolithography (SLA), developed in 1984 as the first 3D printing technology, is now one of the most precise 3D printing processes on the market. Unlike DLP, SLA uses a laser as its light source. The laser beam scans across the moving resin vat, curing the material layer by layer. There are two machine configurations: top-down laser systems (with a platform lowering for each new layer) and bottom-up laser systems (with a rising platform).

SLA delivers smooth surface finishes and layer thicknesses of 0.01–0.05 mm, enabling ultra-thin-layer printing.

Digital Light Processing (DLP), derived from 1980s image projection technology, uses a projector as its light source. A single projection cures the entire resin layer at once. At its core is a Digital Micromirror Device (DMD) between the projector and resin, composed of individually controlled micro-mirrors that reflect light to cure the resin selectively, acting as a mask to harden the material into the desired model.

Some 3D printers have replaced DMD with LCD screens to lower costs, but these solutions are not covered here.

SLA and DLP printing process diagrams. Credit: 3D Hubs / bitfab

DLP is faster than SLA because it cures entire layers instead of point-by-point. DLP printers also tend to be larger, with shallower resin vats than SLA systems.

A final difference lies in maintenance: DLP printers require almost no upkeep and are easier to repair, largely due to the absence of a laser in SLA machines.

1. Print Quality

Print quality is often decisive when choosing between the two technologies, especially for end-use parts where detail, structure, and surface finish matter. Both processes produce high-precision, high-resolution models, but print quality also depends on material selection—most machines use closed material ecosystems tied to manufacturers.

In SLA printing, resin polymerizes point-by-point; longer parts require longer print times, but quality remains consistent regardless of size. SLA achieves a Z-resolution of up to 25 μm.

Credit: Formlabs

DLP supports layer thicknesses down to 5 μm, but projection pixels can create a layer-line (stepped) effect on finished surfaces, and side quality may degrade on long parts (projector light is most concentrated at the build plate center and diffuses toward edges).

2. Technical Features

① Print Speed

DLP holds a clear speed advantage, as it cures full layers in one exposure. Unlike SLA’s point-by-point polymerization, only part height affects DLP print speed.

② Build Volume

SLA is less common for large parts due to high material costs vs. FDM, with build volume limited by resin vat size.

SLA: Formlabs 3L (335 × 200 × 300 mm); 3D Systems Pro X 950 (1500 × 750 × 550 mm)
DLP: EnvisionTEC Xtrem 8K (450 × 371 × 399 mm); Carima DM400A (400 × 330 × 500 mm)

Form 3L offers a larger build volume. Credit: Formlabs

③ Post-Processing

Post-processing is mandatory for all resin 3D printing, as support structures (required for thin models) must be removed after curing—a time-intensive drawback.

For both SLA and DLP, post-processing includes cleaning parts with IPA or TPM, drying, support removal, optional post-curing, sanding, and painting if needed.

Post-processing is labor-intensive and requires expertise, leading some companies to optimize or automate this step.

Removing printed supports is a time-consuming post-processing step.

3. Applications

SLA and DLP serve similar industries, most commonly jewelry and dentistry. For example, Formlabs offers medical-grade resins for surgical guides and other dental/medical devices.

With a wide range of materials, both technologies are also used for prototyping, injection molding, and engineering applications.

Both SLA and DLP deliver high precision.

4. Leading Manufacturers

SLA 3D Printer Manufacturers

3D Systems: Founded by SLA inventor Charles Hull, a pioneer in the technology
Formlabs: A leading SLA provider, offering specialized resins (e.g., Castable Wax 40 for dentistry)
DWS: Supplies SLA-based XFAB printer series

DLP 3D Printer Manufacturers

EnvisionTEC (est. 2002): A DLP technology pioneer
B9 Creator, Asiga: Develop DLP-based printers
Carbon 3D: Uses Digital Light Synthesis (DLS) with oxygen control
Photocentric: Uses Daylight Polymer Printing (DPP)
Prodways (France): Patented MOVINGLight DLP-like technology

EnvisionTEC is a pioneer of DLP 3D printing. Credit: EnvisionTEC

5. Pricing

DLP printers are generally more affordable than SLA systems, with clear distinctions between desktop and industrial models.

SLA Printers

Entry-level: Formlabs Form 2 (145 × 145 × 175 mm, ~145 μm point precision) starting at $2,400; succeeded by Form 3/3L
Average professional: $3,000–$4,000
Industrial: Up to $500,000 (e.g., 3D Systems industrial systems); top-down laser machines are typically more expensive

DLP Printers

Entry-level: Anycubic Photon Zero at ~$200
Professional (dental/jewelry): EnvisionTEC systems at ~$15,000; Asiga professional DLP printers at ~$1,000