Many times we have to correct fails in models exported as stl, faces with misguided normal, holes without closing etc … With this simple trick we can avoid many of these failures during the modeling process.
We assign a color to the inside of the faces of the objects: go to the Display
tab and in the Display Mode
drop-down select Shading
(solid views). When you select either of these two options, click on the check box and select a color in the mixer that appears when you press the Color Backface
When selecting the color we can see that the model that was apparently good has all the normal pointing out, we would have to use the reverse command or repeat the form creation command by adjusting some parameters.
Once corrected we are still seeing parts of the selected color for the inside of the faces, we would have to close the model or give thickness to the surface so that the exported stl does not fail us to open it from the program we use to prepare it for 3d printing (slicer).