The most common are SLA (Stereolithography), the first in the history of 3D printing, and DLP (Digital Light Processing). SLA is a slightly more accurate method, as it works more pointwise using a laser, making it more suitable for making smaller pieces. The light source from two mirrors on the X and Y axes penetrates through a container with resin, which selectively hardens in layers. DLP 3D printing technology uses a projector that has a wider beam of light. The piece is made faster, but not with such precision, so this method is used to make larger pieces. Both technologies are widely used in the dental industry and goldsmithing.