<P> Powders may be applied with a fingerprint brush, a brush with extremely fine fibers designed to hold powder, and deposit it gently on the fingerprint to be revealed, without rubbing away the often delicate residue of the fingerprint itself . They may also be applied by blowing the powder across the fingerprint, or by pouring the powder onto the print, and then blowing away the excess . </P> <P> Magnetic powders are also used, where a fine magnetic powder is held by a magnetic applicator, which may then be gently moved across the fingerprint . As no bristles touch the surface, this often damages the print less than other methods of developing the print . </P> <P> Modern fingerprint powders have a variety of compositions, and are often a matter of personal choice by the expert using them or down to the standard procedure of the department or agency . Many agencies use proprietary powders produced by independent companies, and so the exact formulation of these powders is not revealed . </P> <P> Some surfaces, such as organic ones, do not take to fingerprint powders at all and use of alternate methods is necessary . Other media, such as certain types of glue, can be "smoked" over these surfaces with fair results . </P>

What kind of powder is used for fingerprinting