Wall thickness is the distance between the outer surface of your model and the opposite inner surface. You need to know how thick the wall of your objects is supposed to be and guarantee that your model is thick enough before printing. Is your wall thickness enough for a hollow resin model? When it comes to wall thickness, it is important to understand it so that you can print 3D objects successfully. Creating a hollow model means that you need to design your object with “walls”. If you wanted to save material and money, you may hollow the models out so as to reduce the volume of your models.