Magnetic powders can be used only in combination with a magnetic brush. A mixture of iron and pigment particles, such powder is attracted by the magnet in the head of the magnetic brush, causing the iron particles to form a kind of brush. When the powder has to be returned to the jar, the magnet is drawn up. The broad rim around the head of the magnetic brush prevents the iron particles from following the magnet. Eventually, its attraction to the particles weakens until they fall of the brush. Due to the nature of the powder and the magnetic brush, use on steel objects is not feasible.
Magnetic Jet Black
A deep black, strongly adhering powder providing excellent contrast. This very popular magnetic powder can be used on many surfaces. Examples are: aluminum, candles, and polystyrene foam. Very fresh fingerprints on paper can also be developed with this powder. A special application is in making comparison prints of shoe soles. The soles are coated with a very small amount of silicone oil (for example, from the SLM spray), and an impression is made on a sheet of paper, then visualized with Magnetic Jet Black.
1. The sole of the shoe is rubbed with a cloth on which silicone oil is sprayed.
2. The shoe is pressed on a large enough piece of paper (or worn and then stepped on the paper).
3. The print of the outsole is powdered with Magnetic Jet Black.
4. The resultant print.
Adheres a bit less than Magnetic Jet Black. However, the adhesion to the background when developing prints on dirty surfaces is also reduced.
A special characteristic of this powder is that it works well on plastics and visibility is good, on both light and dark-colored surfaces. When inadvertently too much powder is used, the excess can be removed with an ordinary fingerprint brush.