Which type of fingerprints are clearly visible to the naked eye?

Patent fingerprints are indeed clearly visible to the naked eye. These types of fingerprints are formed when a finger that has been in contact with a colored substance, such as ink, grease, or blood, leaves an impression on a surface. Since these prints are in a contrasting color to the surface they are found on, they can be easily seen without any special processing or enhancement techniques.

The visibility of patent fingerprints makes them particularly useful during initial crime scene investigations, as they can be documented and collected with minimal effort. This characteristic differentiates them from latent fingerprints, which are often invisible and require special techniques to enhance their visibility, such as dusting with powder or using chemical methods. Developed fingerprints, while also visible, typically refer to latent prints that have been treated to make them visible; thus, they do not naturally appear without processing. Undeveloped fingerprints refer to latent impressions that have not been treated or enhanced and are therefore not visible without additional methods.