The effect of ink layer thickness on color rendering (4)

The two color materials are mixed, and the color exhibited great changes with the color material concentration (thickness). The ideal red filter and the green filter are laminated together, and when one unit of white light is incident, different colors appear as the thickness of the filter changes. The color rendering process is shown in Figure 4, with the following expression:

1 1 unit thick red filter and 1 unit thick green filter overlap:
{(Y)+(M)}+{(Y)+(C)}=2(Y)+(M)+(C)→(Bk) Black

2 units thick red filter and unit thick green filter overlap:
{1/2(Y)+1/2(M)}+{1/2(Y)+1/2(C)}=(Y)+1/2(M)+1/2(C)→ 1/2 (Y) Yellow

3 units thick red filter and unit thick green filter overlap:
{1/4(Y)+1/4(M)}+{1/4(Y)+1/4(C)}=1/2(Y)+1/4(M)+1/4( C)→1/4(Y)+1/2(W) light yellow

The color mixture has a darker color, and when the concentration (thickness) of the color material is large, it appears black and the saturation is 0. As the concentration (thickness) decreases, the color gradually appears, the brightness increases, and the saturation increases rapidly. Gradually decrease after reaching a certain level.

Fig. 4 The color mixture is mixed

5, the mixing of the color and the primary color material

The color mixing with the complementary color material exhibits an achromatic color, and the phenomenon that the intermediate color material and the non-complementary color primary color material are mixed and colored becomes more complicated. Taking the ideal red filter and yellow filter overlap as an example, when one unit of white light is incident, the color rendering process is as shown in FIG. 5 , and the expression is as follows:

a) Overlay of 1 unit thick red filter and 1 unit thick yellow filter:
{(Y)+(M)}+(Y)=2(Y)+(M)→(R) Red

b) Stacks of red filters of unit thickness and yellow filters of unit thickness:
{1/2(Y)+1/2(M)}+1/2(Y)=(Y)+1/2(M)→1/2(R)+1/2(Y) Red Yellow

c) Stacks of thick red filters and thick yellow filters overlap:
{1/4(Y)+1/4(M)}+1/4(Y)=1/2(Y)+1/4(M)→1/4(R)+1/4(Y) +1/2(W) light yellow

Interspersed with non-complementary primary color materials, with the difference in concentration (thickness), not only changes in brightness and saturation, but also changes in hue, showing a mixed color concentration (thickness) when the color is large Hue, when the concentration (thickness) decreases, becomes a mixed hue of the intermediate and primary colors.

Figure 5 Mixing of primary and secondary colors

Conclusion

In summary, for the same ink, the color properties may change when the thickness of the ink layer changes, and the effect of the change of the ink layer thickness on the color rendering effect of the primary color, the inter-color, and the complex color ink is also different. Especially for the same kind of intermixed color material, when the thickness changes, there will be a phenomenon that the hue, lightness and saturation all change, that is, the intermixing phenomenon. Similarly, for a certain color-mixed color sample (invariable thickness of the ink layer), when the brightness of the illumination source changes, there will also be changes in hue, lightness, and saturation, which reproduce the printing color and design of the packaging color. Has a certain guiding significance.

From China Packaging
(Author / Lu Xinguang Yang Linping Song Bing)