SLA vs DLP: Guide to Resin 3D Printers

In recent years, 3D printing has become more affordable and accessible, and resin printing in particular has exploded in popularity for its stunning detail. But once you start shopping, you run into two acronyms: SLA and DLP. Both cure liquid resin with light, yet they do it in different ways, and that difference affects speed, detail, and price.

Here is how the two resin technologies compare, and how to choose the right one.

The Core Difference: The Light Source

Both SLA and DLP belong to the same family, vat photopolymerization, where light cures liquid resin layer by layer. What sets them apart is how that light reaches the resin.

SLA (Stereolithography)

SLA uses a single laser point that is steered by mirrors to trace the outline and fill of each layer, curing the resin one path at a time. Because the beam is a fine point, SLA produces smooth, continuous curves and excellent edge quality. Our SLA guide covers the process in more depth.

DLP (Digital Light Processing)

DLP uses a digital projector to flash an entire layer of light at once. The image is made of tiny square pixels, so each layer is cured in a single exposure rather than traced. Most affordable consumer resin printers today use a closely related LCD-based method, sometimes called MSLA, which works on the same whole-layer principle.

Speed

DLP is generally faster. Since it cures a whole layer in one flash, print time depends mostly on the number of layers, not on how much area each layer contains. SLA traces every layer with its laser, so larger or more detailed layers take longer. For batches of parts that fill the plate, DLP has a clear speed advantage.

Detail and Resolution

This is more nuanced. SLA resolution is defined by the laser spot size and can render smooth curves beautifully. DLP resolution is defined by the projector's pixels, so detail is excellent but very large flat areas can show faint pixelation. On a small build area, DLP pixels are tiny and detail is superb; spread over a large plate, each pixel covers more space and resolution drops. SLA does not have this build-area tradeoff.

Cost

Consumer resin printers are overwhelmingly LCD/DLP-style machines because the technology is inexpensive to produce, which is why you can buy a capable resin printer for a few hundred dollars. Laser-based SLA machines tend to sit higher up the price range, especially for larger build volumes.

Side-by-Side

Which Should You Choose?

For most hobbyists printing miniatures, jewelry, or detailed models, a modern LCD/DLP-style resin printer offers the best mix of detail, speed, and price. Choose laser SLA if you want smooth curves across a larger build area and are willing to pay for it. Either way, our resin printer reviews can help you pick, and our FDM vs SLA guide is worth a read if you are still deciding between filament and resin.