Fluorescence is not the same as glow in the dark. It just means that the colours seem a lot brighter. What normally happens, is when light shines on say, a red object, all light is absorbed by that object's colour EXCEPT red, which gets reflected back. So we see just the red colour. Similarly a blue object absorbs all light and just reflects back the blue. But fluoro colours - they absorb all light, but re-emit all light morphed into the colour you see. That's why they seem brighter - they actually emit, but only while there is light shining on them. They don't emit in the dark. That's phosphorescence and is caused by various means but usually at the sub-atomic level.
An interesting side note - absorbing light energy and only re-emitting one end of the spectrum, means that the rest of the energy is still zinging away inside the dye molecule and eventually making it break down chemically. So colours at the low energy end of the spectrum (such as red) actually have to absorb higher energy wavelengths. As a result, it is the red end of the spectrum that has dyes that have more problems with chemical stability. Next time you see a faded picture, note that often it is the red colours that have faded first.
What I love about silk fabric, is the colour you can get in it. But to get that colour by conventional means takes a lot of labour, a lot of water and a lot of effort. There are some natural colours, I remember keeping silkworms as a kid and seeing the cocoons looking like those pastel sugared almonds from Greek weddings. Most of mine were pale yellow, but I remember a few pink ones and white ones. I can't remember what I had done differently in feeding them, but it was common knowledge that if you fed them something different, you would get different colours in the silk.
I had to research the history of domestication for a major assignment for uni, many years ago. I remember being fascinated with the information on silkworms. According to one reference book that went into details, silkworms have been so thoroughly domesticated for so many thousands of years, that trays of them are just left wherever, and the silkworms stay on the trays without trying to go wandering. There have been attempts at other kinds of silk including a Frenchman who made himself some stockings out of spider silk (turned out to not be commercially viable - can't farm spiders for silk).
I can't wait for this new colouring method to be commercially available!
Marg
