Affordable white papers to use with colored pencils. They offer the tooth that is necessary for layering colors and come in weights that are durable enough to use solvents or light applications of water on.
I will mention Vellum at this point because many confuse vellum with bristol vellum and they are different. Vellum was originally made from the skin of a calf. Vellum is now a mixture of plastic and cotton or wood. It is a translucent piece of paper and is a part of invitations usually.
Vellum, when referring to a paper, is a type of finish or texture.
Bristol is a machine-made surface which is heavier than paper, comparable to cardstock. It is available as vellum surface or smooth surface, both of which are relatively smooth. It provides a stiff, strong surface to work on, front and back. It is a 100lb. weight paper.
Bristol is one of my favorite standard papers to use. You mostly notice the difference between the vellum and smooth while you are working. The slight tooth of the vellum surface allows quite a few layers of colored pencil to be applied to its surface. The smooth not so many.
Bristol can handle applications of solvent extremely well. I highly suggest taping the paper to a drawing board if water is going to be used. Bristol can only handle the lightest application of water and it still might buckle.
Bristol is an excellent choice for a beginner colored pencil artist. It is relatively inexpensive and can handle different techniques very well.
Stonehenge paper is a mold-made, 100% cotton, deckle-edge paper that has the ability to take multiple layers of wax- and oil-based colored pencils. Sheets and pads of Stonehenge come in 90lb. Some sheets of Stonehenge are available in a 120lb.Stonehenge Pads are manufactured differently and do not have the deckled edge.
Stonehenge paper takes a lot more layers because of its tooth. You can see and feel the difference between Stonehenge and Bristol. Stonehenge accepts solvents very well, but again with water, the 90lb paper will only take the lightest application and must be taped to a drawing board. It has a greater chance of buckling with water.