*2.5. Dimensional Accuracy and Surface Roughness*

The effects of each post-processing technique on the surface of the FFF parts were firstly investigated through changes in their width, height, and length dimensions. Secondly, changes in mass and surface roughness were also examined. The latter was evaluated in terms of the average roughness (*Ra*) and the average maximum peak-to-valley height of the roughness profile (*Rz*), using a portable roughness gauge Rugosurf 20 from Tesa Technology. The sampling length and cut-off values were set based on the ISO 4288:1996 standard [44].

The surface state of the treated samples was captured using an Olympus DSX1000 digital microscope (Olympus Iberia, Barcelona, Spain) fitted with a DSX10-SXLOB lens and using a 1× and 20× magnification. Surface morphology was examined with a JSM-6460 Scanning Electron Microscope (SEM)(JEOL Ltd., Akishima, Japan).
