SLA 3D Printing Cost Per Gram: Complete Pricing Guide for 2026

Stereolithography (SLA) and Digital Light Processing (DLP) are the two dominant resin-based 3D printing technologies used in modern manufacturing and prototyping. Both methods use a photopolymer resin that cures when exposed to light, but they differ significantly in how that light is applied and the resulting characteristics of printed parts.

SLA uses a laser beam that traces the cross-section of each layer one point at a time. This vector-based approach means that regardless of the part geometry, the laser must traverse every edge and contour individually. The result is extremely high resolution on fine details, particularly in the XY plane, with layer thicknesses typically ranging from 25 to 100 microns. SLA has been commercially available since the 1980s and has a proven track record in dental, jewelry, and engineering applications.

DLP uses a digital light projector to flash an entire single layer at once. The projector displays a grayscale image of the cross-section, and all points in that layer cure simultaneously. This parallel approach generally produces faster build times compared to SLA, especially for parts with large cross-sectional areas. DLP also tends to produce more consistent layer quality because there is no scanning variation.

Surface quality is where DLP often has an advantage. Because the entire layer is projected at once, DLP parts typically have smoother surfaces with no visible striations from scanning paths. SLA parts can sometimes show fine layer lines, though post-processing can minimize this. Both technologies produce parts with excellent feature resolution and smooth surface finishes suitable for visual prototypes and functional parts.

When it comes to accuracy, both technologies can achieve tolerances of plus or minus 0.1mm to plus or minus 0.2mm depending on part geometry and print orientation. SLA excels at capturing fine details due to the precision of the laser spot size, while DLP accuracy is limited by the pixel resolution of the projector. For very small, intricate parts such as dental crowns or jewelry patterns, SLA often outperforms DLP.

Cost considerations favor SLA in terms of printer availability and material costs, though both technologies require expensive proprietary resins. DLP projectors have lamps that eventually need replacement, adding to the total cost of ownership. For high-volume production of consistent parts, DLP may offer better throughput, while SLA remains the preferred choice for intricate prototypes and one-off custom parts.