All Crayola® Crayons are made with paraffin wax and color pigment. The crayons vary slightly in weight due to the amount of color pigment added to make each color as well as the density of the powder pigment itself. Even though certain color pigments are very light, and others are very dense, that doesn’t mean all dark crayons are heavier. Test this in your laboratory by doing an experiment to see which Crayola Crayons float and sink in water.