What can dirty substrates cause in relation to friction ridge prints?

Dirty substrates can interfere with the ability to obtain clear friction ridge prints primarily because contaminants can obscure the details of the print. When such substrates are present, the quality of the impression can be compromised; dirt, grease, or other substances can create a blotchy appearance, which diminishes the clarity necessary for accurate analysis and identification. This muddied appearance can hinder forensic examinations, as small ridge details essential for comparison may be obscured or indistinguishable from the background noise.

In contrast, obtaining perfect or fully detailed prints relies on clean surfaces that can present clear impressions of the friction ridges. The notion of enhancing matrix deposition also implies that contaminants would support the formation of prints, which is not the case; rather, they typically detract from the quality and legibility of the impressions. Therefore, the primary impact of dirty substrates in this context is to make the prints appear blotchy, ultimately rendering them less useful for forensic purposes.