Saturday, March 21, 2009

Textiles and Apparel Industry- Global Challenges and Opportunities 2009 and beyond

The “International Textiles Conference and Exhibition 2009” organized by the Team tech Textiles, India and supported by the leading Textile Associations, who are working for the development of Textile industries in India, Corporate Garment Industries, Leading Textile and Apparel Industries, Textile & Garment Machinery Manufacturers & allied industries, Will be held from 16 April 09 (Thursday) to 18 Apr 09 (Saturday) in Bangalore. Under the theme of “Textiles and Apparel Industry- Global Challenges and Opportunities 2009 and beyond

Speakers from world-renowned fashion industry, Academics, Textile and apparel industry will be participating to share their thoughts on textile technology, R&D, Policy making, marketing to face the challenges, opportunities 2009 and beyond…

for more details visit event website teamtechtextiles

Wednesday, March 18, 2009

Colour and Colour Mixing

A coloured surface appears the coloured because light is reflected from it in that colour's wavelengths only. All other wavelengths predominantly are absorbed by it. A blue object reflects blue light but absorbs most of the red, orange, yellow, green and violet. Black and white is slightly different. They are not, strictly speaking, colours. White surfaces reflect all or nearly all wavelengths and black surfaces absorb them totally. Response curves for the rods (colour sensitive photoreceptors of the human eye). The peak response values occur at 580 nm for red, 540 NM for green, and 440 NM for blue. There is no excitation of the blue cones above 550 NM .The overall response of all three cones together is at 560 NM (yellow-green).

Additive Colour Mixing
The absence of light is darkness, add light to it
Superposition (lamp overlap)
Rapid alternation (biased LED) "persistence of vision"
Small elements (TV pixels, halftones)

The basic rules of additive colour mixing.
red + green = yellow;green + blue = cyan
blue + red = magenta ; red + green + blue = white

Subtractive colour mixing
Subtractive colours are produced when white light falls on a Coloured surface and is partially reflected. The reflected light reaching the human eye produces the sensation of colour. Subtractive colour is based on the three colours Cyan, Magenta and Yellow. Varying the mixture of these primary colours produces other colours. When these three colours are mixed together at 100% they produce black. The absence of CMY pigments would result in white.

Metamerism :
When two object with different spectral graphs present identical coloured appearance in specific lighting and observation conditions, and different appearance when lighting or observation conditions are changed ,then metamerism is said to be in existence. Metameric index (D65 ~ A) = { (LD-LA)2 + (a*D65-a*A)2 +( b*D65 - b*A)2 }1/2