What are the processes used to enhance latent fingerprints?

Latent fingerprints, or "Invisible Prints", are most common and detected with:
-Hard/non-absorbant surfaces: Fingerprint powders are dusted over the surface, sticking to the oils of the print. (Powders are made in different colors to provide contrast with the surface being dusted)
-Light color surfaces: Fine Carbon Powders
-Dark Surfaces: White Aluminum powders
-Fluorescent powder may also be used, photographed under a UV light, stands out on bright surfaces
-Soft/Porous surfaces: Chemical methods reveal latents such as Iodine Fuming (Article is placed in an enclosed cabinet with iodine crystals. Cabinet is heated and iodine vapors are released. Once combined with oils of print, chemical reaction occurs and print is visible.
-Ninhydrin Srays form purple/blue color when combined with Amino Acids in human perspirations

Hope that helped!