Is it possible to make a mirror in Gmod 13?

I’ve been looking all over for an answer on how to make a prop reflective at all, but I haven’t found a thing. It’s really important that I find out how to make a mirror because I need one for this video I am making. Please help me. Even a way to make it look all reflective like would do.

Not sure if this helps, but gm_construct has a mirror in the building opposite of spawn, downstairs.

Garry has stated that, in it’s current state, Source engine is not able to simulate completely reflective surfaces easily.