What effect can dirty substrates have on a friction ridge print?

Dirty substrates can significantly impact the clarity and quality of friction ridge prints. When a substrate is contaminated with dirt, oils, or other materials, it can obscure the details of the print. As a result, the print may appear blotchy. This blotchiness occurs because the contaminants interfere with the natural ridges and valleys of the print, making it difficult to discern the finer details that would otherwise be recognizable. Thus, the presence of dirt creates an irregular pattern over the print, leading to a less defined appearance and ultimately affecting the ability to analyze and match the print accurately.