I have a project a from a friend where I am going to be creating a model and 3D printing it. However, I can't seem to figure out what this surface finish is called. At first, I thought that it was a knurled surface but it does not appear to be so. I am thinking that it is a pitted surface. But, I do not know how to create a pattern such as this one.
These are a rail set for a URX 3 rail.