What does the matrix of a friction ridge print consist of?

The matrix of a friction ridge print is comprised of a combination of sweat and foreign materials. This mixture is crucial for the formation of latent prints, which are the impressions left behind by the ridges of a person's fingers on a surface. The perspiration produced by sweat glands contains water as well as various organic substances such as salts, amino acids, and proteins, which contribute to the fingerprint's composition.

Foreign materials can include substances that the individual comes into contact with, such as dirt, oils, cosmetics, or other compounds that may be present on the skin. When these elements combine with sweat, they create a unique matrix that can be transferred onto surfaces, forming the distinct patterns utilized in forensic examinations. This combination is vital for the visibility and analysis of latent prints, enabling investigators to identify individuals based on their unique ridge patterns.

Other choices focus on components that are too narrow or singular. For instance, while moisture, oil, or dried residues can be constituents of a friction ridge print, they do not encompass the comprehensive nature of the matrix that includes various materials from the skin and the environment. Therefore, the selection that highlights a combination of sweat and foreign materials captures the full picture of what constitutes the matrix of a friction ridge print.