Digital Light Processing (DLP)

Digital Light Processing (DLP) cures liquid resin with projected light to create small plastic parts with fine detail, smooth surfaces, and moderate mechanical performance.

Overview

Digital Light Processing (DLP) is a resin-based 3D printing process that uses a projected light pattern to cure entire layers of photopolymer at once. This delivers high resolution, sharp edges, and smooth surfaces, especially suited to small, intricate plastic parts. Layer heights typically range from 25–100 microns, with excellent feature definition on fine text, micro-channels, and small fillets.

Use DLP when you need high-detail prototypes, master patterns, or functional components that are small to medium in size and don’t see extreme loads or temperatures. It excels in dental, jewelry, microfluidics, and consumer product work where visual quality and fine features matter more than maximum toughness. Tradeoffs include limited build size, resin brittleness compared to engineering thermoplastics, and sensitivity to UV and moisture over time. Part accuracy depends heavily on orientation and support strategy, so expect some tuning for tight-tolerance fits and mating features.

Common Materials

  • Standard photopolymer resin
  • Tough photopolymer resin
  • High-temperature photopolymer resin
  • Dental biocompatible resin
  • Castable photopolymer resin

Tolerances

±0.002" to ±0.005"

Applications

  • Dental models and aligner molds
  • Jewelry patterns and castable masters
  • Small electronic enclosures and bezels
  • Microfluidic chips and small channels
  • Fine-detail cosmetic prototypes
  • Small connectors and snap-fit features for light duty use

When to Choose Digital Light Processing (DLP)

Choose DLP for small to medium plastic parts where fine detail, smooth surfaces, and crisp edges are more important than maximum toughness or large build volume. It suits prototypes, patterns, and light-duty functional parts that benefit from high resolution and consistent surface quality. Ideal when you need production-like appearance quickly from a digital design.

vs Fused Deposition Modeling (FDM)

Pick DLP over FDM when you need much finer details, smoother surfaces, and small, precise features without extensive post-sanding. DLP is a better fit for small cosmetic parts, intricate geometries, and patterns where layer lines and nozzle limitations from FDM would compromise function or appearance.

vs Stereolithography (SLA)

Choose DLP over SLA when you need very fine detail on small parts and value fast print times across the whole layer. DLP’s pixel-based exposure often gives sharper small features and better throughput on tightly packed small components, though at the cost of build area and some limitations from pixel resolution.

vs Selective Laser Sintering (SLS)

Select DLP over SLS when surface finish, sharp detail, and visual quality matter more than mechanical robustness and temperature resistance. For small cosmetic housings, prototypes, or dental and jewelry work, DLP produces smoother, more accurate surfaces than the grainy sintered texture common with SLS nylon parts.

vs Multi Jet Fusion (MJF)

Use DLP instead of MJF when you prioritize ultra-fine features, smooth surfaces, and translucent or castable resins rather than tough, production-grade nylon. For optical prototypes, dental models, or investment casting patterns, DLP’s resin chemistries and surface quality usually outperform MJF’s powder-based finish.

vs PolyJet

Choose DLP over PolyJet when you want high-detail resin parts at lower part cost and can live without multi-material or full-color capability. DLP often offers similar or better resolution for small, single-material components, with simpler post-processing and fewer concerns about long-term material creep from very soft PolyJet elastomers.

Design Considerations

  • Keep parts relatively small and compact; very large flat areas can warp or show cure variation due to projector uniformity limits
  • Avoid ultra-thin free-standing walls; target ≥0.4–0.6 mm thickness and add ribs instead of large unsupported panels to reduce warping and breakage
  • Design clear support access and sacrificial surfaces so supports can be removed without damaging cosmetic or critical areas
  • Orient tight-tolerance features away from the build plate and away from heavy support regions to minimize distortion and post-processing impact
  • Add generous fillets at internal corners and transitions to reduce stress concentrations and improve print success on small features
  • Specify functional tolerances clearly on mating features and allow for light sanding or reaming if you need press fits or precise alignment