Pigments

I found it is always good to have a basic understanding of the pigment you use .One way the obtain this information is through a colour chart, they are invaluable to obtain information of the colours whether they are transparent ,semi/transparent staining etc .Taking note of the pigment numbers is a good way to see if the colour is the same from one brand to another as different brands call the pigments by various names there can be minor differences basically the same hue.
PY is for a Yellow
PR is for a Red
PB is for a Blue
This 2 letters are in front of all pigment numbers and now most house brands display this on the product.Artist want this information so that they can pigments choose wisely.