Showing posts with label dichroic glass. Show all posts
Showing posts with label dichroic glass. Show all posts

Friday, April 27, 2007

What is Dichroic Glass?


I am often asked "Do you use any paint on your pieces?". The answer is "no, although I would like to try that technique as well. Many of my pieces are made with dichroic glass, a type of glass that has grown in popularity dramatically." Here is a brief overview of what dichroic glass is and how it is made....

The word "dichroic" is derived from two Greek roots, "di" for two and "chroma" for color. So "dichroic" literally means "two-colored", especially when viewed from different angles or from transmitted to reflected light. This bi-colored effect is produced by a process called "thin film physics". Thin-film physics also explains rainbows in soap bubbles, the swirling colors in a thin layer of oil floating on water, and the vibrant iridescent reflections on a dragonfly's wings. To make dichroic glass, metallic oxides (such as titanium, silicon, and magnesium) are heated in a vacuum chamber to very high temperatures, using a high-voltage electron beam, until they are vaporized and deposited onto the surface of glass. The thickness of the oxide on the glass is determined by time and temperature.

Dichroic glass is a high-tech spin-off of the space industry. It was developed for the laser industry but it has become one of the most popular materials used by glass artists today. The brilliance of dichroic glass in natural light or sunlight is truly amazing. Pictures just do not do justice to the depth and play of color. There are many challenges involved in using dichroic glass to make art glass jewelry, not to mention cost. Once a raw sheet of dichroic glass is fused, its characteristics will change yet again with the new colors shifting towards the blue end of the spectrum. That is why I am often waiting impatiently for my kiln to cool properly so that I may see how my pieces turned out. It is all too tempting to open the kiln door too early to take a peak!!

Wednesday, April 11, 2007

Not all glass is created equally...






Examples above are of an art glass pendant, a dichroic pendant, and a millefiore pendant.


Glass fusing has become quite popular. But as a buyer of glass jewelry it is imperative that you buy your glass pieces from an experienced glass artist. Improperly fused glass can crack and break apart on you for no apparent reason. It is important to know how to combine the glass properly since you cannot mix different co-efficient glasses. I work with various types of glasses that have co-efficients of 90, 96, and 104. In addition, it is important that the glass is properly annealed for strength and durability. Annealing is the process by which the glass cools and contracts. It must be done at a certain speed and rate of temperature. Often I will set my kiln to hold certain temperatures for periods of time to ensure the proper annealing. I have also heard many stories about pieces being improperly adhered to bails. I only use a special 2 part epoxy for glass and metal which is carefully cured. I also score up the surfaces so that they adhere better. Curing takes time and it must be done properly. So, the moral is...don't be fooled by cheap imitations...they aren't worth it in the long run.