New method for objective hiding assessment of wall paint

 
The intrinsic hiding power of a paint is very well described by the theory of Kubelka and Munk, resulting in what is often called a theoretical spread rate. This number expresses the number of square meter of wall that can be covered at a certain contrast ratio. The test method assumes a very uniform application, which can be realized under lab conditions, but does not necessarily corresponds to the hiding power of a paint layer applied with a roller. Such a roller creates, pending on the flow characteristics of the paint, the substrate, the type of roller, a more or less pronounced surface structure (peaks and valleys), resulting in a reduction of the observed hiding power. In this paper we describe how this surface structure can be quantified via statistical image analysis of the paint surface after roller application on a black substrate.