Sandblasting is a method which is used quite extensively in heavy duty cleaning of abrasive surfaces such as brick cleaning & car rust or dirt. It is also used in areas of Art & Design particulalry in glass or metal workshops.
Sandblasting glass is etching of the surface leaving a rough, frosted surface. The final design on a glass pane is placed in a vacuum (sandblaster). A spray gun with a suitably fitted nozzle (for the type of sand/ grit) is then triggered & sand and grit under high pressure blast over the design until the clear glass is entirely frosted. The amount that you etch into the glass is controlled by how far or near the glass you use/ hold the gun from the design.
In designing I use a heavy duty tape (specific tapes withstand pressure from a sandblaster) which completely covers the surface of the glass before I begin. Then using a craft knife I cut out a design which I have already hand drawn on the taped surface beforehand as a guide, whether that is a portrait, figure or pattern. This leaves areas with & without tape, it is the areas that are cut out which get sandblasted (frosted appearance) and the taped areas remain clear (once the tape is removed after sandblasting).