Failure of paint to dry to a smooth film, resulting in unsightly brush and roller marks after the paint dries.
Use of low-quality paint
Use of low-quality tools/wrong roller cover
Re-brushing or re-rolling areas that are partially dried
Too much heat – usually above 90 ºF – or too little humidity, which causes rapid drying of the paint, preventing the film from flowing out properly
Use of paint not specifically made with good flow and leveling properties
When using a roller, be sure to use a cover with the correct nap length for the type of paint being used. Use of a high-quality brush is important – a poor brush can result in brush marks and uneven appearance.
Avoid painting under conditions that cause rapid drying of the paint.
Use a high-quality paint formulated with ingredients that enhance flow and leveling.