My beloved Dick Blick Art Materials has posted a very nice little FAQ for painters new to oils. I really appreciate their explanation of the difference between Artist’s grade & Student’s grade paints:
“What is the difference between Artist and Student grade paints?
Both artist grade and traditional student grade oil paints are made by packing fluid oil with pigment to get a stiff paste. The difference between them is that traditional student grade has less pigment, with the remaining pigment being replaced by extenders. This lowers the price, tinting strength, and opacity. Also, the color selection of student paint lines is generally limited to colors using low-cost, non-toxic pigments, which means there will be hues. Hues may not mix as cleanly as single pigment colors because they’re a blend of pigments.”
The last sentence is a great example of why I try to always select artist’s grade – hues can be very frustrating! But even some artist’s grade colors will come in hues, so keep your eyes open.