Hiding Power and Transparency

The transparency of a pigmented system denotes its ability to scatter light as Uttle as possible. The color change of a transparent pigmented system when applied to a black substrate has to be very small the lower the color change, the higher is 

The definition of hiding power is based on a black and white contrasting support upon which the film of coating is applied. The thickness h of the applied film is determined at the point at which the contrasting surface just disappears, as judged 

A modem well-equipped color measurement laboratory can use the principle of spectral evaluation described above [1.38] to simulate this procedure with a computer. The thickness of the hiding film can then be calculated in advance from the reflectance curves of a single film on a black/white substrate at a known film thickness. 

Transparency. Transparency is expressed quantitatively as the transparency number. This is defined as the reciprocal of the increase in color difference AE b on a black substrate obtained on increasing the film thickness h of the pigmented medium. The transparency number has the unit mm ( = L/m2). It indicates the number of liters of pigmented medium needed to coat 1 m2 of a black substrate in order to obtain a color difference of AE%b = 1 relative to this substrate. In a simplified method the transparency number can be determined by evaluating one or two points on the straight part of the AE b(h) curve. A computer method is more exact, furthermore calculations can be made using the spectral principle of spectral evaluation (see above). For standards, see Table 1 ( Transparency ). 

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Transparent inks n. Inks which lack hiding power and permit light to pass through. They permit previous printing to show through, the two colors blending to... 

Finishing not only improves the application properties of a pigment, such as hue, tinctorial strength, brilliance, transparency/hiding power, dispersibility, and flow behavior, but also considerably enhances its lightfastness and weatherfastness and its solvent and migration resistance. 

Disazopyrazolone pigments, for instance, can be tailor-made for various applications in order to provide features such as high transparency or good hiding power, easy dispersibility, and high tinctorial strength. 

P.O.36 is a reddish, somewhat dull orange pigment which provides very good lightfastness and weatherfastness. It is a highly important pigment. The commercially available types differ considerably in their hiding power/transparency. Different types vary even in terms of shade - the opaque version is redder and noticeably cleaner - and other properties, as well as fastness properties. 

OPACITY. The optical density of material, usually a pigment the opposite of transparency. A colorant or paint of high opacity is said to have a good hiding power or covering power, by which is meant its ability to conceal another tint or shade over which it is applied. See also Paints and Coatings. 

Significant pigment attributes are tinctorial strength, durability (photochemical stability), hiding power, transparency, and heat and solvent resistance. Other properties include brightness (saturation), gloss, rheol-ogy, crystal stability, bleed resistance, flocculation resistance, and other properties associated with specialized applications. 

Features Inc. transparency and hiding power permits higher pigment loading... 

Features Inc. transparency and hiding power permits higher pigment loading exc. compat. with all common paint binders incl. NC and thermoplastic acrylics... 

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