Method I: Sandblast(etch)
A selected surface area is roughened by high pressure and speed stream into frost effect, the imprint is permanent.
Method II: laser engraving inside
First make 2D or 3D file for engraving, second the laser machine would produce pulse in short time, and make a broke inside of crystal/glass, form a tiny white dot. And many white dots to draw the 2D or 3D image inside of crystal/glass.
Method III: UV print
The logo or picture of text would be printed by a film on the surface. It is suitable for colorful content, and lasting without
acid or chemical liquid touching.