Understanding the Difference
To understand the difference between the various grades of paint, we must first understand the basics of how paint is made. From acrylics, alkyd, oils and watercolor all paints are made by combining a pigment (the color) and binder (the medium). There are a few exceptions but this will hold true for 99% of colors that can be purchased.
With this in mind, highest quality oil paint that one would want to use would be paint made from just two ingredients pigment and oil. However, unless you are making the paint yourself you probably will not find paint like this to use. You may even find that a paint made this way is lacking specific characteristics you desire. Additives can be used to give paint more desirable stability, flow and drying properties.
Paint manufactures will use various additives to make the paint perform well for the artist after sitting on a shelf, potentially for many months.
Artist Grade
Artist Grade (Professional) paint will have the highest amount of pigment added, with a minimum addition of additives. This will give the artist grade paint the best tinting strength and opacity, not to mention a higher price tag. However, even in the most expensive paints, additives are needed to produce the highest quality product. For example there are some pigments so strong that if they were mixed with just oil they would overpower any color mixed with them. Also remember that oil paint has been produced for centuries with some manufacturers making paint for over a century and a half. They have had plenty of time to perfect their paints.
The color selection for artist grade colors will also be greater. Some pigments are just more expensive to purchase while others require special safety precautions to produce. Each factor will drive up the cost of paint.
Student Grade Paints
The main purpose for Student Grade (Economy) paint is to be affordable to artist on a budget. The paint is made with the same pigments but less is used during in the manufacturing of the paint. The pigment that is taken out will be replaced with a neutral extender. This will reduce the tinting strength, and the opacity but will also reduce the cost. Student grade paints also come in fewer color choices. The most expensive pigments for the manufacturer to work with, such as cadmium, cobalt, and cerulean will be replaced with a chemical equivalent known as a Hue.
These Hue pigments are not exclusive to the student grade paint line. They are also used to make professional quality paints. They do not have the same properties as the true pigment so it is often assumed that their quality is inferior.
Which one should you choose?
Only you can determine which paint is right for what you are painting. I know when I was a student, cost was the most significant factor when buying paint. I primarily stuck with the less expensive student grade oils. Once I left school I was determined to never use student grade paints ever again. Now I am beginning to realize that there is a place for less expensive paint in preparatory paintings. Once a subject matter has been worked out and the final painting is to begin, this is when the best quality paints should be used.
