Unlike most paints, which get their color from pigment, the majority of inks and candy colors get their color using dye. The difference between pigments and dyes comes down to chemistry. Pigments are suspended in the base while dyes are dissolved.
Pigments are finely ground particles of color which are suspended in the paint which when applies will lay on top of a surface. Dyes are chemicals that completely dissolve into the base medium to create color. When applied they will chemically bind to the surface and actually become part of it. Dye based inks and paints are very transparent as light goes directly through dyes.
Inks – Most calligraphy and drawing inks use dye for coloring Winsor Newton, Higgins, Pinata. However India ink and acrylic inks (such as FW) are pigmented. Inks work well in an airbrush. Being so thin they spray perfectly with no need for reduction. They spray best at a lower pressure (15-20 psi.) Keep in mind that most inks are very transparent and are easily absorbed. They work best on paper or illustration board.
Candies – Automotive candy paints are also dye colored. Whether solvent-based like Custom Paints’ Inspire Candies or a water/solvent hybrid like Auto-Air Candy2.0, candy colors are very transparent and work best when applied over a metallic base color or flake.