Resolution is one way of measuring the print quality of a 3D printer. Unfortunately, there is no standard that all 3D printer manufacturers adhere to. Each tends to explain resolution using different parameters.
Because 3D printers print in three dimensions, X, Y, and Z, you need a couple of numbers to determine a printer’s resolution. The Z-axis resolution number is often found on spec sheets, but its importance to print quality is not as high as that of the XY resolution. XY resolution is an indicator of minimum feature size. It’s the smallest movement the deposition technology can make in a layer. It is sometimes known as horizontal resolution. Unfortunately, the XY number is not always found in a vendor’s spec sheets.
In general, look for the minimum feature size for the XY plane and then look for the printer’s layer height. Together, these numbers will give a fairly good idea of the resolution your particular 3D printer can execute.
Some quick tips:
The feature size of stereolithography 3D printers is a function of printer optics and the properties of the photopolymer. Stereolithography 3D printers can produce features as small as the diameter of the laser spot.
In general, laser based 3D printers offer more feature accuracy. DLP-based 3D printers are not quite as accurate in part detail due to their fixed matrix of pixels.
In extrusion-based printers, the nozzle opening partially affects resolution. Material properties, such as thermal reaction and drying time, are other factors that affect resolution.
In powder-based systems, resolution is affected by the size of the powder granules and how the material behaves when melted, in addition to the size of the laser beam.