Clean the glass surface thoroughly to remove any dirt, grease or oils and try to keep it this clean throughout the whole project. Using water-based pigment inks, use a rubber stamp or leaf to make a direct print onto the glass. (If you're working with cylindrical glass objects, this is often more easily accomplished by rolling the glass over the stamp than by trying to roll the stamp around the glass.) Dust this ink image with a detail grade embossing powder. Use a small brush to remove any renegade specks and heat. This will then create a detailed resist to the etching cream.

On the glass, mask off an area around and slightly larger than your image. Use adhesive tape to define this area, or lay Contact Paper® over the area and cut away the desired shape. In either case, be sure that the tape is firmly pressed onto the glass to eliminate leaks beyond the edges. Apply etching cream over your resist image and into the exposed shape. It can be brushed on as per instructions on the product label, or it can be applied with a plastic palette knife and spread around evenly with a small foam-tipped dauber.

After being allowed to work, the cream and our resist image can be rinsed away, and the border tape removed. Clean the glass and all tools thoroughly... arid there ya go!

The above is the general approach to the etching with rubber images. Specifically, there are several things that need to be addressed.

INKS
There are two basic criteria for the ink used: 1) it must be colored in order for us to see it on the glass, and 2) it must be sticky enough to both adhere to the glass and hold the embossing powder. The ink suggested above was water-based pigment inks. Although it is possible to use the kinds of inks we find in pigment pads used with rubber stamps, this ink is often too watery and can cause the rubber to slide around on the glass when we try to transfer a print. I find a more traditional relief printing ink - like water-based Speedball® ink - suitable for this task as it is thicker, stickier and still easily removed when necessary. (Oil-based relief ink is my preferred medium, but students often recoil at the thought of using mineral spirits or paint thinner to clean their rubber. This is a debatable issue.)

Using relief printing inks usually means crafters must use a brayer to roll out a thin layer ink on a glass or Plexiglass® plate and then transfer ink to the rubber. The viscous and tacky nature of this kind of ink does a better job of keeping the rubber from sliding on the glass when we transfer a print.

GLASS CONFIGURATION 
For the beginner, flat glass or truly cylindrical glass (straight-sided tumblers and many styles of bottles) is preferred. The flatness of the printing area of a rubber stamp is easily transferred to these kinds of work surfaces. Bulbous or fluted glass objects present extra special problems as the surface has a multi-dimensional character. This problem will not be addressed in the specific in this class.

EMBOSSING POWDERS 
Detail grade thermography powders would, obviously, provide more detail when creating our resist. But detail powders have a tendency to stick to areas of our glass surface when we least desire it. Standard grade powders work well enough as the weight of the individual grains cause them to naturally fall off the areas of the glass where they are not wanted and yet still stick to the print we've made which sets up our resist.

MASKING 
Once we have our image embossed, the outer resist needs to be applied. This will define the border for our design.

When you apply the adhesive tape or Contact Paper®, be careful to press around the resist image and not directly on it. This will help prevent lifting off our embossed image when we remove the unwanted masking. After we've cut away the desired shape for our project, use a small piece of tissue or cloth to firmly press the remaining edges to as to prevent any etching fluid from leaking under and spoiling our efforts.

Some adhesive tapes designated at "removable" have a water soluble adhesive and should be avoided. The etching cream may loosen the mask and flow unwanted hither, thither and yon.

(*NOTE: Glass etching products are highly caustic and can cause serious injury. Be careful with this stuff!  Follow manufacturers directions carefully and always wear protective clothing and goggles.  Be mindful of local environmental conditions when disposing of used product.)