SLA: SLA (stereolithography) is a resin 3D printing process in which a laser cures liquid photopolymer layer by layer to build a solid part.
SLA, stereolithography, was the first commercial 3D printing process. A UV laser traces each layer’s cross-section on a vat of liquid resin, which hardens where the light lands; the platform moves and the next layer is drawn. SLA, DLP and masked LCD printers all belong to the family called vat photopolymerisation. They differ in how the light reaches the resin.
What it means for the price
Resin costs far more per kilogram than filament, so material is a bigger share of an SLA price than of an FDM one. Build time has two parts: the laser’s trace time, which grows with the area of each layer, and a fixed recoat or peel time per layer, so tall parts take time even when they are thin. Labour is a large line: washing, post-curing under UV, cutting off supports and sanding the marks they leave.
Example: a part that needs 30 ml of a resin bought at €150 per litre carries €4.50 of resin before supports and waste are added. The figures are an example.
Common confusions
“SLA” is often used loosely for every kind of resin printing, including DLP and LCD printers that cure a whole layer at once. Hollowing a chunky part can cut its resin use sharply, but only with drain holes.
Quotometry prices SLA, DLP and LCD resin printing today. See what drives resin printing cost and the resin process page.
Go deeper: Resin printing cost: how to price SLA, DLP and MSLA prints