Tag Archives: powder

Black Powder Processing

By Pat A. Wertheim

This article originally appeared in “Minutiae”, The Lightning Powder Co. Newsletter, No. 42, May-June 1997, p. 6.

Although old-fashioned black powder is the workhorse of fingerprint development
techniques for crime scene use and is also an important method in the laboratory,
maximizing the effectiveness of powder requires far more sophistication than
simply dipping a brush into the jar of powder and painting it onto a surface.

More control can be exercised over black powder by working out of a shallow
dish. The perfect disposable dish can be made by cutting or tearing a blank
inked fingerprint card from any edge into the center of the card. Overlap
the two edges of the cut by about an inch (two or three centimeters) and
tape the card back together to make the dish. A large laboratory weighing
dish may be used, or any other shallow dish or bowl. Place one-half to one
teaspoon of powder (approximately one millilitre) into the dish. Continue reading