In the 1970s Rainbow Studio developed a photographic etching process that at the time was proprietary. This was before the days of computer cut masking and the only practical way to etch intricate or exact designs such as typefaces was by means of manufactured stencils, a costly proposition. What we did was find a rubber like material that was both strong enough to resist sand blasting and photographically sensitive. The process involved coating glass or stone with a thin layer of this emulsion, letting it dry, placing a negative over the surface and then exposing it to UV light. The areas that were exposed firmed up, those that were covered were dissolved with water. The material was re-dried, sandblasted, and stripped.
In 1981 Binswanger Glass, based in Memphis, bid for and won the contract to etch the 55,000 names in the Vietnam Memorial that was designed by Maya Lin. Binswanger came to Rainbow for the process that we had developed. In 1982, led by long time Rainbow associate Cindy Sharp, the black African granite slabs were delivered to Memphis and the process began. After several months the memorial was completed and shipped to Washington. Cindy still does work for the company and is responsible for many notable installations.
In the early 1990s Rainbow worked again on a Maya Lin project. This time it was the Civil Rights Memorial in Montgomery, AL. Rainbow provided all of the photographic stencils for this remarkable installation. We provided the graphic layout as well. The etched verbiage was leafed with palladium to give a silver look but without the problem of tarnishing. 24 kt gold is a more common fill for our etching and on the darker stones is truly impressive. All of the donor plaques at St. Jude Childrens Research Hospital are gold leafed Dakota Mahogany granite. Rainbow is honored to have been continually selected by institutions all over the country for the etched graphics we produce.