Dissolving water less than predetermined standard can make the paint too high in viscosity, and causes roller marks. Alternatively, rolling paint on surface with high temperature, rolling too much paint, or using improper roller can also be the cause of problem.
Besides, using low-quality paint can result in inefficient blending. Paint which sets too fast or duplication of rolling on surface which is in the middle of flash time is also the cause of roller marks.
Sand the affected area with sanding paper. Clean the surface and refinish. Proportionately dissolve paint and water. Avoid rolling the paint when the surface has high temperature. If necessary, add more water and avoid rolling over the surface which is in the middle of flash time.
Select fine roller or one with appropriate bristles that suit the paint and working conditions, for example, a long-bristled roller is more opt to leave roller marks than rollers with medium or short bristles. However, short-bristled roller retains more paint than long-bristled roller.