One part of ski waxing that again only has to do with friction is how to deal with contaminates in snow. These can be anything from sticks, dirt, dust, and tree sap to birch seeds, and grass.  In this case, wax is not the fastest substance to coat the bottom of your ski. For contaminates, the harder the wax the better, but because it is not always cold when the snow is dirty graphite wax is used often as a dirt repellent.

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