What is the difference between Oil Paint Sticks and Oil Pastels?

Both oil pastels and oil paint sticks are made with pigments, waxes, and oils, but their composition and properties differ. Oil pastels have a higher wax content and are made with non-drying oils, such as mineral or castor oil. Water-soluble oil paint sticks contain linseed oil and dry like traditional oil paints. Oil pastels, however, will always remain tacky and require glass protection to preserve finished work.