Student grade acrylics have a lower pigment to binder ratio than thier professional counterparts, offering a quailty product at a more ecnomic price point. Acrylic paint is much like any other paint in that it is made from a simple combination of ground pigment and binder. The pigment is what gives the paint its color. The binder is what gives the paint its consistency and many of its working characteristics. The binders used to manufacture acrylics are acrylic polymers. These acrylic polymers allow the paint to become a plastic film when dry. This is why many other forms of media do not adhere well to acrylic paints after they dry. The plastic film is simply too slick for other media to adhere to the surface. On the good side, this characteristic makes acrylic paintings extremely durable. Many acrylic paints are useful for both indoor and outdoor applications.