Make a see through sphere

[R^T]

this is really random but am trying to make a see through sphere.

I need to be able to put a little bit of paper in it so you can read it.

The only idea I have had is to find a sphere mould and fill it with PVA glue and leave it to dry (not sure if it will dry see through)

Other idea is using a glue gun.

Anyone know any other good ideas?

is there some sort of gel I can buy?

Thanks