Twist off the head of your ball point pen refill, and then slide the ball mechanism out of the refill. The ball mechanism may slide out of the front or back of the refill, depending on the refill's design.
Airbrushing is an artistic technique that utilizes a stream of paint to create artwork. Unlike a can of spray paint, airbrush machines allow you to achieve varying degrees of color intensities with your designs. If you're new to airbrushing, the cost of an airbrushing machine may discourage you from wanting to experiment with the technique. Build your own airbrush at home, and learn the airbrush technique without having to purchase a professional machine.
Push the syringe's handle down. Dip the tip of your syringe into a can of paint, and then pull out the syringe's handle to draw the paint into the syringe's reservoir.
Bend the syringe's needle to roughly a 25 degree angle at its center. Poke the tip of the syringe into the plastic portion near the head of the refill.
Stick the compressed air can's straw into the mouth of the can's nozzle. Slide the other end of the straw into the back of the pen refill.
Hold the syringe above the pen refill, so that paint drips down into the refill's chamber. Tilt the air can's nozzle forward to spray air through the refill and a cloud of paint out of the tip of the refill. Use the syringe's handle to throttle the flow of paint through the pen refill tube to achieve heavier or lighter tones.