1. Leveling property

During printing, if the ink has good leveling properties, the glossiness will be good. If the ink has poor leveling properties, it will be easy to draw, and the glossiness will be poor.

2. Fluidity

The greater the fluidity of the ink, the larger the print size, the larger the dots, the thinner the ink layer, and the poorer the glossiness. The smaller the fluidity of the ink, the less penetration it can reduce, making it easier to flatten the ink film and the higher the glossiness of printed product.

However, if the ink fluidity is too small, the ink is not easy to transfer, which is not conducive to printing. Therefore, in order to obtain better glossiness, the fluidity of the ink should be controlled.

Increasing the viscosity or reducing the fluidity must take into account other printing conditions.

3. Fineness

If the ink particles are coarse, it is easy to cause film stacking and other issues during printing. The printed product is rough, with diffuse reflection and poor gloss.

On the contrary, if the gloss is good, you should pay attention when choosing ink (especially gold ink and silver ink).

4. Viscosity

The viscosity should not be too high or too low. If it is too high, the rubber cloth will peel off from printed surface, and cause stringing. If it is too low, the print size will expand, the ink layer will become thinner, and the glossiness will change.

5. Drying methods

The same amount of ink with different drying methods will have different glossiness. Generally, oxidation film drying has higher glossiness than penetration drying, because the ink printed by oxidation film drying has more binders on the surface.

While the ink printed by penetration drying has less binders on the surface. When the ink is transferred to the paper, the solvent part of the binder penetrates into the paper at a faster speed. The coating and paper fibers absorb the binder. The rougher the paper, the stronger its ability to absorb the binder.

Before the oxidation film drying, the binder is mostly absorbed by the paper fibers. The remaining small part of the binder and pigment particles adhere to the surface of the paper, making the product dull.

6. Transparency

After the highly transparent ink forms an ink film color layer, part of the incident light is reflected by the ink film surface. The other part reaches, and is reflected again, forming two color filtering.

This complex reflection mechanism enriches the color effect, while the color layer ink film formed by opaque pigments, its glossiness is only obtained by surface reflection. The gloss effect is definitely not as good as transparent ink.

7. Glossiness of the binder

The main components of ink are binders and pigments. Glossiness of the binder is the factor that determines whether the ink print can produce gloss.

The early ink binders were made of vegetable oils such as linseed oil, tung oil, and catalpa oil. The surface smoothness of the print after conjunctiva was not high. It could only present a fatty film surface, which formed diffuse reflection of the incident light, and the glossiness of the print was poor.

Now, the binder is mainly composed of resin. The surface smoothness of the print after conjunctiva is high. The diffuse reflection of the incident light is reduced, so the glossiness of the print is several times higher than that of oil ink.

8. Thickness of ink layer

Generally, single-color printed products rarely have glossiness. If overprinting is done on top, glossiness will appear. Therefore, the thickness of each color ink layer has an impact on glossiness.

For example, a thicker ink layer can lay the foundation for improving glossiness, and more overprinting can fill the paper surface and improve glossiness.