The Sandblasting Process
First, a few key elements are needed. Your glass, or "canvas". An air compressor. Sandblasting tools, ie; syphon gun, pressure pot. Vinyl. Cutting knives. A design and some pencils. This is a basic overlay of what is used, but it's a general idea. Oh yeah, respirator and goggles!!
Side note: Most modern glass sandblasters use computer software and plotters to create and cut their designs. This is fine if you want what everyone else has. Personally, 94% of the work I do is drawn and cut by me, using my own designs. This is how I learned and what I know. This also ensures a unique end product.
There are many methods and styles, depending on if the end look is of surface etching (tones and for thin glass), or for deeper carving (more dramatic, sculpted, thicker glass). We'll go with a scenario where the client wants their front door's glass panel etched with a heron scene.
After the design is sketched and agreed upon, a thin vinyl with adhesive is laid on the glass and the design is drawn to scale. The drawing is sort of like a map. Again, different glass etchers have their own method they use. I've heard of a number sequence, "pull sheet", to keep track of what is lifted and when. I tend to rely on my mind's eye.
Once the design is drawn it's time to cut the design. Using a couple different kinds of X-ACTO knives, the lines are followed, just like drawing it but with really sharp blades! Now you're making a stencil.
Now the fun begins! Power up your compressor---air pressure is very important! The air pressure, traveling through an air hose, is what causes the abrasive to etch the glass' surface.
Put on your respirator, goggles, and get ready to get sandy!! (at least, that's how I work!).
To achieve tones or shades, certain pieces or sections are lifted at certain times to achieve the desired look.
Air pressure to your nozzle, distance, angle, all play factors inhow your blasting will look.
The vinyl is the "resist", which means whatever is left on the glass will keep that area from being etched. So as you lift you expose more, so make sure you don't reblast what you already lifted, or you may lose the look you were going for.
Once the design is done, clean it off and you've got an etched panel!