Lap marks occur when one coat of paint is applied over another before the first coat has had a chance to completely dry. This can result in an uneven finish with visible brush or roller marks. Avoiding lap marks is important for achieving a smooth, professional-looking paint job.
There are several ways to avoid lap marks. First, make sure that the surface you are painting is clean and free of dust and debris. Second, apply thin, even coats of paint, and allow each coat to dry completely before applying the next. Third, use a brush or roller that is the appropriate size for the job, and avoid overworking the paint.