The latest generation of consumer and prosumer MSLA printers now offer 12K and 14K LCD resolution, bringing per-pixel resolution below 20 microns on machines under $500. This has narrowed the gap between desktop resin printing and industrial SLA at the detail level, though material options and build volume still favor industrial platforms. Service bureaus running these machines can now offer SLA-class surface quality at significantly lower cost per part than traditional industrial SLA.
Both SLA and DLP print with photopolymer resin. Both produce smooth, high-detail parts that FDM can't touch. If you're ordering a resin print from a service bureau, the technology underneath matters — it affects speed, resolution uniformity, material availability, and cost. Here's exactly how they differ and which one to ask for.
How SLA Works
SLA uses a UV laser to cure resin one line at a time. The laser draws the cross-section of each layer across the surface of a resin vat — wherever it hits, the liquid solidifies. Then the platform steps by one layer thickness and the laser draws the next one.
The key advantage is consistency. A laser spot is the same size whether it's tracing the center of the build plate or the edge. That uniform resolution is why industrial SLA is the standard for large engineering prototypes, dental models, and investment casting masters — applications where a soft edge at 200mm from center would be a problem. The downside is that more surface area means more tracing time. A large dense layer takes longer than a small one.
Industrial SLA machines (Formlabs, 3D Systems, EnvisionTec) also carry the deepest material libraries — dozens of validated resins covering engineering, dental, biocompatible, castable, and high-temp applications.
How DLP Works
DLP swaps the tracing laser for a digital projector. Rather than drawing each layer point by point, the projector flashes the entire cross-section in one image. The whole layer cures at once, regardless of how large or detailed it is.
That's the speed advantage: print time scales with build height, not layer area. A plate full of small parts that takes four hours on SLA might finish in ninety minutes on DLP. The trade-off is pixel size. A 4K projector covering a 200mm build plate has pixels around 50 microns across — but stretch that same projector to a 300mm plate and those pixels grow with it. Bigger build volume, lower resolution at the edges.
The Third Option: MSLA (LCD Resin Printing)
MSLA uses a monochrome LCD screen as a mask between a UV backlight and the resin vat. The screen displays each layer pattern; the light cures through it. Like DLP, the entire layer exposes at once — same speed advantage, similar pixel-size logic.
MSLA is what's inside nearly every consumer desktop resin printer: Elegoo Saturn, Anycubic Photon, Phrozen Sonic Mighty. It's cheaper to build than a DLP projector system, and modern 8K–12K LCD panels now hit resolutions that rival entry-level industrial SLA. When a service bureau offers resin printing at $5–$10 per job, they're almost certainly running MSLA. That's not a cut corner — for most prototype work, the results are identical to industrial SLA at a fraction of the cost.
SLA vs DLP vs MSLA: Side-by-Side Comparison
| Factor | SLA | DLP | MSLA (LCD) |
|---|---|---|---|
| How it cures | Laser traces layer | Projector flashes full layer | LCD mask + UV light |
| Speed | Slower — scales with layer area | Fast — one flash per layer | Fast — one exposure per layer |
| Resolution consistency | Uniform across build area | Degrades at edges and larger plates | Uniform (fixed pixel pitch) |
| Material options | Widest — dozens of engineered resins | Moderate | Growing but narrower |
| Build volume | Up to 500mm+ (industrial) | Typically 150–300mm | Typically 150–330mm |
| Typical cost at bureau | Higher ($8–$25/cm³) | Moderate ($7–$18/cm³) | Lower ($5–$14/cm³) |
| Best for | Engineering parts, large or precise geometry, validated materials | Speed-critical, batch production of small parts | Consumer prototypes, miniatures, cost-sensitive jobs |
Resolution: The Detail That Actually Matters
All three technologies are capable of layer heights between 25 and 100 microns — layers thin enough that you cannot feel them with your fingernail on a finished part. At 50 microns, all three produce surfaces that need no sanding to look smooth. The resolution difference that matters is in the XY plane (the horizontal detail), not the Z axis (layer height).
Industrial SLA typically achieves an XY spot size of 85 to 140 microns — comparable to a medium-fine laser. DLP and MSLA pixel size depends on the projector/panel resolution and the build plate size. A 4K 8.9-inch LCD covering a 218 × 122mm print area has a pixel pitch of about 51 microns — sharper than industrial SLA at smaller scales.
The practical takeaway: for most prototype applications at the service bureau level, you won't see a meaningful resolution difference between SLA, DLP, and MSLA on parts that fit within their respective build areas. The difference becomes visible only on very small features (under 0.3mm) or very large builds where DLP pixel size grows with the projection area.
When SLA Beats DLP
Large parts requiring consistent edge-to-edge resolution. A 300mm architectural detail model at 1:20 scale needs sharp features across the entire build plate. Industrial SLA's constant laser spot size delivers this; DLP's pixels grow at the plate edges.
Specific validated materials. If your application requires a specific Formlabs Dental SG or 3D Systems Accura resin that has undergone biocompatibility testing, regulatory submission, or material characterization, that material exists only on SLA platforms.
Castable and investment casting masters. Most castable resins — those designed to burn out cleanly in a lost-wax casting process — are formulated for industrial SLA. The burn-out profile is calibrated for SLA cure characteristics, and using the wrong resin on a DLP or MSLA machine can cause casting defects.
When DLP or MSLA Beats SLA
Small detailed parts in quantity. If you need 50 miniature game pieces or 20 dental aligners, DLP or MSLA finishes the job in a fraction of the time SLA needs. The full-layer-at-once exposure means print time doesn't scale with the number of parts on the plate — only build height matters.
Cost-sensitive prototypes where material choice is flexible. MSLA at a service bureau typically costs 30–50% less per cubic centimeter than industrial SLA. If your prototype doesn't require a specific engineered resin, MSLA delivers comparable quality at lower cost.
Consumer and maker applications. For hobbyist use, cosplay props, tabletop gaming miniatures, and custom jewelry prototypes, MSLA on a modern consumer machine is difficult to beat on cost and availability.
You need a specific validated or engineering resin, your part is large and requires consistent edge-to-edge detail, or you're making investment casting masters.
You're printing many small parts, turnaround time matters, cost is a primary constraint, or your application is miniatures, jewelry, dental models, or consumer prototyping.
What to Ask a Service Bureau
When ordering a resin print from a service bureau, the technology label on their website often matters less than the specifics. Ask:
- What machine are you running? — Formlabs Form 4 (SLA), EnvisionTec (DLP), Elegoo Saturn 4 Ultra (MSLA) will give you a clear picture
- What resin options are available? — Confirm the specific material is in stock, not just listed
- What is the pixel/laser spot size at my part dimensions? — For critical detail work, verify XY resolution for your build size
- Do you have ISO or material certifications? — Required if your application is medical, dental, or food-adjacent
Not sure what your resin print will cost? Use the 3DPrintMap cost estimator to get a price range across budget, mid-range, and premium service bureau tiers before you reach out.
Find SLA / Resin Printing Services →Frequently Asked Questions
For very small parts with fine detail — miniatures, jewelry masters, dental models — DLP and MSLA often win because their fixed pixel pitch delivers consistent resolution across the entire build plate. Industrial SLA is also excellent for fine detail, but consumer SLA machines have a wider laser spot size than a typical 4K DLP projector pixel. For large parts with fine detail, industrial SLA maintains consistent resolution better than DLP, whose pixels get physically larger at bigger build plate sizes.
DLP cures an entire layer at once with a single flash from a projector. SLA traces each layer line by line with a laser — the more surface area in a layer, the longer it takes. On small parts the difference is minor, but on large flat layers or when printing many parts at once, DLP can be dramatically faster. MSLA (LCD) works the same way as DLP in this regard — the full layer is exposed simultaneously.
SLA has significantly more material options, particularly at the industrial and engineering level. Industrial SLA machines support dozens of specialty resins: rigid, flexible, castable, dental, biocompatible, high-temp, and ceramic-filled. DLP and MSLA machines have a narrower material library, especially on desktop machines. If you need a specific engineering resin or biocompatible material, SLA is almost always the right call.
MSLA (Masked Stereolithography) uses an LCD screen as a masking layer between a UV light source and the resin vat — the screen displays the layer pattern and light cures through it. Like DLP, the entire layer is exposed simultaneously, making it fast. MSLA is the technology in most consumer desktop resin printers (Elegoo, Anycubic, Phrozen). It's cheaper than both traditional SLA and DLP projector machines, with comparable resolution at the desktop scale. Most service bureaus offering low-cost resin printing are running MSLA machines.