The main question when it comes to ink is "What are the ink properties that influence ink consumption"?
We will observe some of these properties below.
1. Color Gamut
The volume of the color gamut reflects the accessible colors on a printer system in combination with a defined ink set.
The following parameters influence the color gamut.
1.1. Pigments and Dyes
The pigment and dye selections define the location of the extreme values of the single and mixed color within the color gamut of an ink set.
The influence of pigment and dye concentration is limited starting from a certain value as saturation curves are not linear.
On surface-forming ink systems, such as UV LED inks, the pigment concentration has a small impact on the performance of the intensity. On the other hand, the physical properties of the final ink layer are massively affected by pigment concentration. Flexibility, abrasion, and adhesion can be negatively affected by extended pigment concentrations.
Dye and pigment concentration have an impact on the graininess of a printing system. The higher the concentration the higher the intensity of every single dot. These effects are visible in light shade areas if light inks are not in use.
1.2. Gloss Level
The gloss level of surface-forming ink systems, such as UV LED inks, has a proportional impact on the volume of the color gamut. High gloss values result in a bigger volume of the color gamut.
The gloss level of inks has a bigger impact on the color gamut volume in some cases compared to pigment concentration variations of such systems.
The gloss level of a surface-forming ink system is mainly influenced by the ink-on-substrate and ink-on-ink interaction during the printing process.
Wetting and spreading mechanisms of the printed droplets before curing are the main contributors to this effect. However, curing effects such as micro-shrinkage of the polymer film also affect the gloss degree of the formed surface. Furthermore, excessive wetting or spreading mechanisms may harm the print quality, as the potential resolution diminishes with higher droplet spreading.
The reduction of the gloss level of an ink set printed in matt mode is predefined by the used chemistry. The gloss level cannot be reduced further by print setting variations. Gloss level increase on the other hand is possible by using predefined, special print modes.
High gloss levels in matt mode printing are unfavored for many indoor applications, though this is mostly based on a subjective rating. The acceptance of the gloss level also has regional differences for such applications.
Figure 1: Left side, microscopic image of a matt printed surface; right side, microscopic image of a glossy printed surface; both 500 x magnification
