Which pigments are better - thick or liquid?

Contrary to popular belief, the density of pigments does not necessarily affect the quality of the result. Thick pigments are not necessarily better than liquid ones. 

In fact, thick pigments are due to thickeners, not necessarily a higher concentration of paint. Therefore, very thick pigments have to be diluted before use. They can be used with short-stroke typewriters, with a small overhang of a needle, or in manual techniques. With a large overhang, the needle may not carry the pigment to the skin. 

Most modern pigments are liquid but very concentrated, with minimal thickeners. They have a water-alcohol base and glycerin to prevent drying out, and their consistency is similar to liquid cream. These pigments are easier to work with long-stroke machines.

Checking concentration: To check the concentration of a dye in a pigment, you can do the following:

1. Put one drop of pigment into a transparent glass of water. A concentrated pigment will color the water brightly and densely, while a weakly concentrated pigment will remain transparent.

2. Put one drop of pigment on a wet cotton pad and grind it. A concentrated pigment will paint over the disc completely, while only stains will remain from a weakly concentrated pigment.