2 .Material Origins - Dichoric Glass

The word “dichroic” is derived from two Greek words “di” meaning “two” and “chroma” for colour. So “dichoric” plainly means “two-coloured”. This is the most distinctive feature of dichoric glass- that it seems to have more than one colour, especially when viewed from varied angles.The origins of this type of glass are ancient and are found in many civilizations throughout history.

So what exactly is dichroic glass and how did it end

up in the world of art?

The first and oldest man-made type of dichroic glass uses metals, such as gold and silver that are evenly mixed throughout the glass to form a type of colloidal dispersion. The metal particles are so small, about 5-200 nanometers, and dispersed so well throughout the glass, that the glass appears entirely homogeneous and monochromatic.

A perfect example of this would be The Lycurgus Cup created in the 4th century AD in Italy. In reflected light the glass appears green. In transmitted light the glass appears red. The cup is in fact on display at the British Museum in London.

The Lycurgus Cup, 4th Century AD, Italy. It appear green (left) when illuminated from the outside and red (right) when illuminated from the inside)

The more recent type of dichroic glass uses a vacuum deposition process to add layers of various metallic oxides on top of the glass such as titanium, chromium, aluminium, zirconium, or magnesium; or silica that are vapourised by an high-voltage electronic beam in a vacuum chamber. The molecules are deposited onto the surface of a blank sheet of usually clear or black glass. The finished glass can have as many as 15 to 50 layers of these materials, yet the thickness of the total coating is approximately 30 to 35 millionths of an inch, so that’s  about 760 to 890 nm. The coating that is created is very similar to a gemstone and by controlling the thickness of the coating, different colors may be obtained.

The history of the latter type of dichroic glass goes back to the 1950's and 60's when NASA’s Department of Defence, developed this as a shield against cosmic radiation. An example of this is the golden sheen on an astronaut's face shield is a dichroic coating meant to protect against the harsh glare of unfiltered sunlight.

Dichroic glass does not use paints, dyes, gels or any standard colurings agents to create colour anymore than a prism does. The fantastic colours are created through the manipulation of light. The multi-coloured effect is the result of complex light interactions called "thin film physics". Thin-film physics are also responsible for rainbow patterns in a soap bubble, the swirling colours of an oil slick floating on a puddle and the dramatic reflections in dragonfly wings.

Uses of Dichoric Coating

Optical use- it is used in microscopes, LCD progectors, 3D movies and sunglasses.

It has also become a popular material used by artists and designers through dichroic coating manufacturers.

A good example of and artist who uses dichoric glass is Chris Wood, who uses it to create installations in urban areas, creating a play with light in building, walls and indoor spaces.

                     Petrie, Chris Wood, St Helens & Knowsley Teaching Hospital, St Helens.

Light Garden, London Bridge Hospital- Chris Wood

1. Hussein Chalayan - The Tangent Flows, Central Saint Martins, 1993

I’ve always been a big admirer of Hussein Chalayan’s work for as long as I have been interested in Fashion and Textiles, simply because of his groundbreaking methods of combining unconventional materials and processes. His 1993 graduation collection titled ‘The Tangent Flows” consisted of a series of buried garments that were unearthed just before the show.

In this collection Chalayan combines textiles with the process of oxidation. Oxidation is the loss of electrons during a reaction by a molecule, atom or ion.When oxygen combines with an element, it changes the appearance of the element. For examples when iron reacts with oxygen and changes to rust.

The collection consists of garments that appear to be decomposed and rotten showing earthy stains in a rusty red shade. The textile used was silk that Chalayan had buried with iron fillings in a garden and exhumed six weeks later. With this he tried to show the audience how quickly fashion dies and how easy it is to recycle. He demonstrates how beautiful the process of decaying and recycling can be.

The structure of the garments are simple yet free spirited. The models almost look as they have walked out of the earth, which has a certain beauty to it. The texture of the silk is very natural, as is the rusty colour due to the extremely natural process the textile has undergone.

While creating this collection, Chalayan has focused attentively on the process rather than the end result, and by doing these unpredictable new forms have been revealed. I like looking at it this way because it emphasizes the importance of the process, not only the finished product and how designers should take risks in their work to produce successful innovative products.

Throughout his career Chalayan has experimented with innovative materials and processes and has explored how technology could create new possibilities in fashion. Some of his notable work includes the ‘After Words’ Autumn/Winter 2000 Womenswear Collection where chairs and tables transformed into wearable extensions and garments on the human body.

The Remote Control Dress, from his Spring/Summer 2000 collection was designed by means of the composite technology used by aircraft engineers that facilitate airplanes to fly by remote control. The dress was created using a combination of fiberglass and resin, was molded into two smooth and glossy pink-colored front and back panels fastened together.

In his most recent show at Paris Fashion Week, Spring Summer 2016, he presented models wearing stiff-looking, collared overcoats standing under what appeared to be a shower. The garments appeared to simply disappear when it came in contact with the water. Underneath, the white dresses were encrusted with Swarovski jewels and intricate black appliqués, which were revealed as the first white layer of fabric dissolved.