On which type of paper is Physical Developer particularly effective?

Physical Developer is particularly effective on wetted paper because it works by rehydrating and enhancing the visualization of latent fingerprints that have been left behind on surfaces that have retained moisture or been exposed to some level of water. When latent prints are developed using Physical Developer, the process involves converting metal salts into metallic silver, which can then visualize the print against the background of the paper.

Wetted paper provides the necessary conditions for the reagents in Physical Developer to interact with both the moisture present and the components of the latent print. This method is highly useful in forensic science because many latent prints may become more prominent when the necessary moisture is available, which allows for better lifting and subsequent analysis.

Other types of paper, such as dry or glossy paper, may not provide the ideal conditions for the Physical Developer to work effectively. Dry paper lacks the moisture needed for optimum development of latent prints, while glossy paper can repel water and hinder the necessary chemical interaction. Recycled paper, on the other hand, may have varying textures and treatments that could interfere with the development process, making wetted paper the most reliable choice for utilizing Physical Developer.