What is Lapping?
You recently painted your wall, but you can clearly see the layers overlapping on the surface? Lapping can occur during the paint application process, especially when there are wet and dry layers that tend to overlap when applying paint. What is known as a “wet edge” must be maintained when painting on any surface. Paint should be brushed or rolled on from wet to dry, instead of vice versa. As it is, natural breaks in painting should be taken into considerations, such as near windows or doors.
Acrylic or latex paints can make it easier for visible lapping to occur, since the nature of the paint is such that the content makes lapped areas less visible. Reducing wet edge time is also key; so that wet and dry surfaces do not meet as much and cause lapping. Furthermore, alkyd paints have higher wet edge properties, and are the preferable paint to be used to avoid lapping during paint application.
Porous surfaces also need to be taken into consideration before applying certain paints, so that lapping does not occur. To ensure lapping does not occur or is not as noticeable, make sure that a wet edge technique is maintained during the paint application process, and acrylic or latex paints, preferably alkyd based paint, is used during the process.