Bi-chromatic Powder
Bi-chromatic powder does well on multi-colored surfaces. The surfaces that can be used to test Bi-chromatic powder include;
- White backing card
- Dark backing card
- Paper
- Untreated wood
- Non-porous smooth surfaces such as plastic and glass
- Non-porous rough services such as leather, vinyl and textured countertops
- Adhesive tapes
- Soda can
- Computer paper
- Painted wood
- Unfinished wood
Most surfaces encountered during investigations are multi-colored. Investigators do not have prior knowledge of the color of the surface that they will find. However, the analysis of the collected evidence allows considering a variety of surfaces. The bi-chromatic powder is made using a combination of black and aluminum powder. The idea behind the use of black and aluminum powder is to make the powder usable on a variety of surfaces. Generally, the powder does well when tested on white and dark backing cards. Also, porous paper and untreated wood form a useful surface for testing bi-chromatic powder. Furthermore, the powder may be tested on non-porous surfaces such as the plastic and glass, which are smooth. However, the use of smooth surfaces does not outdo the effectiveness of non-porous rough surfaces such as leather and textured countertops. Exceptional conditions also exist in the testing of bi-chromatic powder where human skin, adhesive tapes, and blood prints are available for use. Generally, the bi-chromatic powder works perfectly on surfaces that would give misleading results if other powders were used. Besides, the bi-chromatic powder ensures that the marks left behind after lifting the prints are ridges that cannot provide misleading information. Furthermore, investigation using bi-chromatic powder is authentic and provides reliable results. Generally, the bi-chromatic powder is less selective on the number of surfaces to be tested.