Glass is Easy:
Glass is one of the easiest materials to learn to work with and can produce good results with a little practice. Practice is the magic word here. If you wish to produce really great artistic results: Practice and more practice.
Start with an old jam jar or a pickle jar or whatever you got. Eat the pickles! Only practice on empty jars. Seriously, some people want to etch on full bottles of beer or sparkling wine. The chance of the bottle bursting from the pressure inside and the slightly weakened glass, may be small, but I would not take a chance on it.
Use a diamond bit (sometimes called an engraving point) which is just a nice piece of steel with some fine industrial diamonds glued on the end. Most engraving accessory bits are 3/32in. diameter shank ( or shafts). This means that you must have a 3/32in. collet to fit the 3/32in. bit into your HSRT. Also, for engraving, I like to use the Flex-shaft. It gives a little better control for the fine work. I use a Dremel #7144 bit which has a slightly rounded taper to a fine point. Other manufacturers make diamond bits and you can experiment, on your pickle jar, with different shapes to get you get the finish you are looking for. Hold the bit at a low angle to the glass, about 10 or 20 degrees, ( see photo ), press gently on the glass and slowly move the bit from right to left. Wipe the accumulated dust off, often, so you can see your progress. Practice "freehand" for a while then try a pattern. Tip:. When working with clear glass, print your design or pattern on your computer, then tape it inside the glass. You may have to trim the pattern a bit to compensate for any taper in the glass, and adjust for the thickness of the glass when you are etching, but this is a good way to get an accurate design. If you can't see thru the glass, or if you are working on a mirror, get a wax pencil at the art store. Tip:. An "eyebrow" pencil works pretty good. Sketch your design and then etch with your diamond!
If you are working on fragile glass or glass with raw edges, wear protective gloves.
Your diamond bits can help you do amazing things with stained glass. Etching fine details, that cannot be done with copper foil or lead, will add a new dimension to your art. Diamond bits can be used to help alter the shape a little to improve the fit between pieces. A diamond "drum" shape, like the Dremel # 7123 works best for this. Any of the larger diamond bits can be used to remove sharp edges from your glass.