Tone or Color

According to recent understanding, impairment of the Hghtfastness and weather resistance of Ti02 pigments proceeds according to the following cycle [2.66]  

Molecules of water are bound to the Ti02 surface, forming hydroxyl groups on 

Absorption of light of short wavelength (anatase 385 nm, rutile 415 nm) occurs, producing an electron and an electron defect or hole (exciton) in the crystal lattice, which migrate to the surface of the pigment. 

At the surface of the pigment, an OH ion is oxidized to an OH radical by an electron hole . The OH ion is then desorbed and can oxidatively break down the binder. A Ti ion is simultaneously produced by reduction of Ti with the remaining electron of the exciton. 

The latter reacts with and is converted into an H02- radical. 

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Thermogram - A thermal map or image of a target where the gray tones or color hues correspond to the distribution of infrared thermal radiant energy over the surface of the target (qualitative thermogram) when correctly processed and... 

Fiber blends can be dyed into union shades (tone-on-tone) or multicolor effects can be obtained by coloring the individual components in different shades or by maintaining one fiber in an undyed state (reserving). A complete reserving of a fiber is not possible in all cases. 

Attempts to transfer and so print images have been made previously. In the past there has not been a successful attempt to provide a single universal material, which can be used both in xerographic photocopiers, laser printers and the like and also permit transfer of full-color images from one surface to another without the use of intermediate means, such as adhesive materials and without loss of definition or color tones or image quality. 

The development of the mica-based pigments started with pearlescent colors (Fig. 76 A, TiOz - mica). It was followed by brilliant, mass-tone-colored combination pigments (i.e., mica, Ti02, and another metal oxide) with one color (interference color same as mass tone) or two colors (interference and mass tone different) that depend on composition and viewing angle (Fig. 76 B). In the 1980s further development was made by coating mica particles with transparent layers of iron(III) oxide (Fig. 76 C) [5.222]. 

Red cabbage as a colorant source has been studied for many years. As of 1990 at least one firm has introduced San Red RC, the first commercially available food color derived from red cabbage. The color can be used alone or in combination with other colors to create strawberry, cherry, raspberry, and blueberry tones. By way of proprietary technology, the new dye is claimed to be free of flavor and odor defects, which in the past have been associated with red cabbage. The dye is pH dependent. The color tones move toward blue-red as the pH value increases. San Red RC ranks between cochineal and grape juice in percent or color retention. 

With a sense of color, people can see more aspects of their world, in more detail. Without color, with only black and white and gray, the eye can see a mere dozen or so different tones. With color, the eye can see thousands of distinctions, which not only look different than one another but also convey different feelings and associations. Psychologically, gray is dull and negative. With color, warmth and coldness, excitement and stimulation, and countless other human expressions are conveyed. 

TO MAKE THE CAKE AS PICTURED ON PAGE 30, bake two batches of cake in 8- and 6-inch pans. It s best to use two of each size for two layers. Extra batter from the 6-inch cake can be used to fill a small tray filled with cupcake liners. Prepare the Love Blossom flowers a few days before (page 226) and the Vanilla Whipped Buttercream (page 84), tinted pale lemon yellow. Use at least three different colors for the flowers, in pink tones—or as I do for baby boy showers, shades of pale blue. Fill, frost, and chill the cakes, then follow the directions to tier the layers on page 242-... 

Changes and variations in image tone may not always be as glaringly apparent. Often the difference is subtle, so much so that someone viewing a print might not even be aware that it is neutral, cool, or warm, unless the fact is drawn to their attention, or they see an example of each, side-by-side. The simplest test to determine whether or not a paper is cold-, warm-, or neutral-toned, is to develop it for two minutes in a neutral tone developer such as D-72 and compare it to other papers developed similarly. If a paper is warm- or cold-toned the color can be seen in the shadows. 

The application of a highly reflective gold film (see Section 3.1) by vapor deposition or sputtering can help alleviate this problem in optical microscopy. When used with certain materials, however, this causes the loss of valuable information that would normally be conveyed by gray tones or other colors of the material s phases. Most oxide and non-oxide ceramics can be examined by optical microscopy without requiring color. However, this is not true for the microscopic examination of classic ceramic materials, e.g., stoneware, porcelain, refractory materials, or cement clinker. In these cases, thin sections are used to exploit the material s transparency, which allows it to be examined by transmission microscopy. 

Mass tone (mass color) According to ASTM, when viewed by reflected light, the color of a pigment-vehicle mixture of a thickness that completely obscures the background is known as mass tone or mass color. 

Image display tone - Gray shade or color hue on a thermogram. 

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