My printer said he uses pigmented inks. What does that mean?

There are two types of inks in use for fine art production. Dye based and pigmented. Dye based inks are bright, saturated, and they produce outstanding prints. Pigmented inks are made by grinding base colors and creating the colors used in the inks. These are color solids mixed with a liquid carrier. They are dull in comparison to the dye inks.

The big difference, even though dye based inks are exceptional in their color reproduction... they fade rapidly. I have seen dye base inks fade within days when placed in the sun. Pigmented inks do not fade or fade so slowly you don't notice it. You can make up for the lack in brilliance by using glossy top coats on your final prints