Colour bright white

The pulps obtained from chemical pulping are brown in colour and, whilst suitable for many applications, are unsuitable for printing and writing papers which require a bright white pulp. Both chemical and mechanical pulps often require bleaching for many end uses. The colour of these pulps is mainly due to residual lignin ( 3—6%, see Table 2.2 in Chapter 2) although products derived from carbohydrate may also make a contribution. The approach to removal of colour is different in each case. 

QUANDROS - is a Stone or jewel which is found in the brain and head of the Vulture, and is of a bright white colour. It fills the breasts with milk, and is said to be a safeguard against dangerous accidents. 

Fig. 30.2 Thorotrast liver dark brown colouring of the liver surface with reticular bright white fibrosis...

Shen F, He F, Lu D et al (2006) Bright and colour stable white polymer light-emitting diodes. Semi Sci Tech 22 L16-L19... 

But while asking questions concerning whether a series of colours are complementary, we are in fact asking two questions at once we ask about the colour in relation to how dark or light it is ( What is the brightness of the colour ) but we also ask a more subjective question, saying Is the pink more red or more white what kind of pink is it We are looking for two types of relationship. 

These essentially colourless compounds have been defined as substances that, when added to an uncoloured or a coloured substrate, increase the reflectance of the substrate in the visible region by converting UV radiation into visible light and so increase the whiteness or brightness of the substrate . The air of uncertainty in the final clause of this definition... 

The system used by colourists in the dyes and pigments industry is the so-called CIELAB system. [Note CIELUV is the one used in the display industries (Chapter 3).] In this system the three-dimensional nature of colour space is taken into account namely hue (the colour attributes), saturation (the absence of white grey of black) and lightness (also called brightness). In CIELAB colour space the coordinate L is a measure of hghtness-darkness, where a perfect black is 0 i.e. zero whiteness) and a perfect white is 100 a correlates with red (-Ea ) and green (-a ) and b with... 

Features Rootbark is a bright, rusty brown, soft and brittle. Short, corky, layered fracture, with many oil cells. Chips of the woody root are commonly used—they are brownish-white in colour, showing concentric rings and slender medullary rays. 

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