Last time we talked about how the fill density set in the 3D printing software will affect the hardness of a 3D print. This time we are going to talk about another setting "the perimeter shell/Number of Shells", which can also affect the hardness of a printout.
The more shells you set in the 3D printing software (3D slicing software), the harder the printout will have. In general, the number of shells has already been set to be 2 in default in the 3D printing software, and 2 shells is good enough. This is because besides setting the shells, you will at the same time set the fill density as well, therefore both fill density and number of shells will determine the hardness of a printout.
As the number of shell was set to be 2 in default in the 3D printing software, users normally don't need to do any adjustment on this setting. On the other hand, it is easy to adjust the number of shell in the 3D printing software. For example, in the Flashprint 3D printing software, users can simply type in the number of shell they want as shown below: