We are using Stereolithography (SLA) 3D printing to create transparent objects that, with some post-processing, can be made optically clear.
Applications for transparent resins vary from see-through decorative pieces to optical elements like prisms. They are also used in research, for example to examin the flow dynamics of liquids before investing in expensive tooling for injection molding or glass production.
Normally, when optically clear resin is printed, the resulting print is somewhat translucent, but not exactly transparent. To achieve a transparent surface the parts are processed with a varnish or hand polished to have clear transparent “glasslike” finish.