Wall thickness

Wall thickness is simply how thick your printed object is from side to side. Wall thickness directly applies to the strength of that section of the piece. Technically, you could have walls as thin as your extrusion width. You could have your printer print a single line of plastic thread for your entire piece and there are many examples of beautiful vases printed in that manner.

Depending on your application, that may not be the best plan of attack. A thin wall of 0.42mm is easy to break. Our first model in this book is a pendant based on the profile of one of my sons. This is a sentimental piece. Surely, I would not want the clasp to break during my daily activities. I would want to give the hook for the pendant enough strength to survive the wear and tear of my daily life. On the other hand, railing detailing on a house figurine would be purely decorative and not be subject to the same stress. I could go smaller there.

Another thing to consider is how this section of your print is attached to the rest of the model. If it is a wall connected to other sections on two or more sides, it is considered a supported wall. It does not have to have to be as thick as a wall that stands by itself, an unsupported wall. The front wall of a house figurine is an example of a supported wall. It is attached to many other sides, the left side of the house, the right side of the house, the roofing. On the other hand, the thickness of a profile pendant, I would consider an unsupported wall:

The front wall of a house is a supported wall. The thickness of a profile pendant is an unsupported wall.

It is not a hard and fast rule, and you may fine-tune what works best with your printer. As a starting point for your design requirements, I tend to give supported walls at least 1mm in thickness and unsupported walls at least 2mm in thickness. For sections that I feel may need extra strength, I consider sizing those portions up to 3-5mm.