Printing, pre-press, publishing and photography services – yesterday, today and tomorrow

Contents:

1. The Milling Process
2. Leafing Pigments
3. Nonleafing Grades
4. Aesthetic Properties
5. Vehicle Selection
6. Uses
7. Metallics

Metallics

Metallic colors have been used to a limited degree in printing. However, there is an increase in the use of these colors in recent years. What are metallic colors? Simply, they are combinations of aluminum pigments with other pigments. These combinations produce new colors. When one considers the number of different grades of aluminum pigments that can be used at various loadings and the number of color pigments available, the potential for new colors is endless.

Offset printing has used metallic colors effectively in literature designs to emphasize a particular idea. However, bright metallic colors are not often achieved. This is due to several factors, such as using very fine leafing pigments and an extremely thin ink film applied to the substrate. The fine particles of aluminum mask the colors. To obtain the brightest colors possible, transparent organic pigments should be used with the aluminum pigment.

Brilliant metallic colors can be obtained in fluid inks. To achieve these bright colors, nonleafing and preferably sparkling, nonleafing pigments should be used. These, in combination with transparent organic pigments or dyes, will produce their best results, because these aluminum pigments have a controlled particle distribution, and the number of particles is greatly reduced.

The sparkling grades are special nonleafing pigments that have a narrow particle distribution and a highly reflective surface. In some grades, the particle geometry is also controlled, which produces an even cleaner metallic color. In general, one should avoid using leafing pigments, as they contain too many fine particles, have a broad particle distribution and will produce "dirty" colors. The leafing pigments also float to the surface of the film and hide the metallic color.

Quite often, golds are made using aluminum pigments. These are known as synthetic golds. A bright metallic gold color can be achieved by using the sparkle nonleafing grades in combination with clear, transparent yellow and red pigments.

The shade of gold can be varied by selection of different particle sizes of aluminum pigments and with the addition of various quantities of red pigment. While these synthetic golds might not match the bronze pigments, they can produce a bright, attractive gold.

Aluminum pigments have a versatile use in printing inks. They can produce a variety of shades of silver with the correct selection of aluminum flakes. Bright metallic colors can be obtained especially in the area of fluid inks when one uses sparkling aluminum pigments. Consumer packaging attracts buyers when aluminum pigments are combined with transparent organic pigments to create new and exciting colors.

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