Charcoal drawing can be a messy medium. The charcoal can smudge and smear easily just by coming in light contact with another surface. The drawing can even smear while you are working on it, just with a brush of your palm. Protect your hard work by using a fixative to seal the charcoal in place. A fixative is an aerosol spray that sets the charcoal to the page and protects it. It is as easy to use as hair spray, and you may even substitute hair spray for fixative in a pinch, though this is not preferred for superior long-term results.
Take the charcoal drawing to an area with good ventilation. Outdoors is best. A breezeway works, too.
Lay the charcoal drawing flat. Alternatively, you may pin it up on a wall.
Shake the fixative can for a few seconds.
Spray the charcoal drawing. Start at the top. Sweep from right to left and back. Work your way to the bottom. Move in a steady flow. Do not saturate the charcoal drawing.
Spray the drawing again. This time go top to bottom and back up to the top, working your way across the drawing. This crossways coating ensures good coverage.
Allow the charcoal drawing to dry. This should take a few minutes.
Work over the fixative if you desire. The areas fixed should stay put, and you may draw further over them without fear of smearing.