Stereolithography cures liquid photopolymer with a laser tracing each layer, and it was the first commercial additive process. It remains the reference for accuracy and surface quality among resin machines, and its parts are the ones most often mistaken for injection mouldings when photographed.
How it differs from other resin machines
A laser traces the outline and interior of each layer, so feature accuracy is set by the beam and the optics rather than by a pixel grid. That gives excellent edge definition and makes it strong on large parts where a projected image would have to be tiled. Machines using a projector or a screen are faster on small parts and stereolithography stays competitive on size and on fine features.
Materials and what they suit
General purpose resins for appearance and fit. Tough and durable resins that approximate the behaviour of common thermoplastics. High temperature resins for tooling and testing. Clear resins that polish to genuine transparency. Castable resins that burn out cleanly for investment casting, which is a major use in jewellery and dental work.
Post processing decides the result
Parts come off supported, wet with uncured resin, and green. Washing, support removal, sanding of the support witness and a controlled post cure are all needed, and a clear part additionally needs sanding and polishing or a clear coat to reach optical transparency. The quoted price should say which of these are included, because the labour is significant.
Using it for function
Stereolithography parts are accurate and comparatively brittle. They make excellent masters for silicone tooling, excellent appearance models and excellent fit checks. They make poor snap fits and poor load bearing brackets. Where a functional resin part is needed, choose a tough grade deliberately and test it rather than assuming the general purpose material will do.
Questions people ask about sla printing service
What is SLA printing?
Stereolithography: curing liquid photopolymer layer by layer with a laser. It was the first commercial additive process and is still a reference for accuracy and surface.
Is SLA better than other resin printing?
It is stronger on large parts and fine feature definition. Projector and screen based machines are usually faster on small parts. Both are photopolymer processes.
Can SLA parts be used functionally?
For fit and appearance, yes. For load bearing or snap fitting parts, choose a tough resin deliberately, and consider sintered nylon or machining instead.
Why do clear SLA parts look cloudy?
Because the as printed surface scatters light. Genuine transparency needs sanding and polishing or a clear coat, which is labour that should be in the quote.