Dimensional deviations in the various 3D printing processes

SLA (stereolithography):  ± 0.2 % (with a lower limit of ± 0.2 mm)

• The stereolithography (SLA including DLP), together with Polyjet, is the most accurate method. The diameter of the laser is usually between 100 and 150 µm. This is much less compared to the FDM method.  
• This results in fewer tolerances and the surface of the component can be optimally printed.

Multi Jet Modeling/Polyjet: ± 0.1 – 0.2 % (with a lower limit of ± 0.1 – 0.2 mm)

• The Polyjet process is used with UV radiation and in contrast to processing with heat, very low tolerance values occur here. This is recommended for components that are very delicate or have partially thin walls, since less stress or shrinkage of the material occurs due to the UV process.

FDM:  (Fused Deposition Modeling) / FFF (Fused Filament Fabrication: ± 0.2 % (with a lower value of ± 0.2 mm)

• The FDM process is the coarsest of the usual 3D printing processes, with a nozzle size of normally 0.4 mm and a resulting minimum wall thickness of 0.8-1 mm. Depending on the material, deformation plays a role and influences the achievable accuracy.
• The surfaces are usually rougher than the other methods and the layer structure clearly visible.