Non fluorescing substrates were chosen to avoid the overlapping of background fluorescence with that of treated fingerprints. Later, fluorescing PMMA substrates were used in the TR imaging experiments. Fluorescent powder was applied by means of a magnetic brush onto the latent fingerprint samples. Generally, these types of powders are most effective to develop the prints on non-porous surfaces. Care was taken to apply the powder almost uniformly onto fingerprint samples.
The powder being investigated were ultra yellow, ultra orange-yellow, ultra red, ultra gold, ultra green, ultra azure-blue and ultra white. All these powders are obtained from Medtech Forensics.