The surface of parts made by 3D printing is rough,so that we can not make the crystal clear prototype by 3D printing process directly,but the translucent prototype. It need to takes two steps before the parts made by 3D printing are crystal clear.
1.Get translucent prototype by 3D printing.
2.Grinding and polishing the prototype to make the surface are smooth and transparent.After that,it will be more clear if painting the varnish.