Which substance is effectively developed using ninhydrin?

Ninhydrin is a chemical used primarily for developing latent prints on porous surfaces, making it effective for that purpose. When ninhydrin is applied to such surfaces, it reacts with amino acids present in the sweat residue left by fingers, producing a colored compound called Ruhemann’s purple. This reaction allows for the visualization of latent prints that would otherwise be invisible, especially on materials like paper, cardboard, or fabric that can absorb moisture and organic substances.

The other options do not align with the specific capabilities of ninhydrin. Plastic impressions are usually developed using other techniques that can capture three-dimensional features, such as casting. Dry ink prints would be better analyzed using methods appropriate for non-porous surfaces, like superglue fuming or powder dusting.T Similarly, visible prints on glass do not require chemical development like ninhydrin, as they are already discernible to the naked eye. Therefore, the most appropriate and effective use of ninhydrin is for latent prints specifically on porous surfaces.