A fibrous nonwoven mat particularly suited for hiding the color of a substrate when the mat is bonded to the substrate is made by forming a web of fibers from a wet fibrous slurry, saturating the mat with a resinous binder containing 1-20 weight percent of a paper coating material, removing excess binder from the mat to produce a mat having a resin binder content of 5-25 weight percent and drying the mat. The mat has high hiding power for substrates like board or blanket of fiber glass insulation and other colored materials.