1 Preparation: The first step is to prepare the room for painting. This includes covering the floors and furniture with drop cloths, removing switch plates and outlet covers, and filling any holes or cracks in the walls.

2 Cleaning: The walls must be cleaned thoroughly to ensure that the paint adheres properly. A mixture of water and mild detergent is used to clean the walls.

3 Sanding and Priming: Once the walls are clean and dry, they are sanded to smooth out any imperfections. Then, a coat of primer is applied to create a smooth surface and improve paint adhesion.

4 Painting: After the primer has dried, the painting can begin. Professional painters use high-quality paint and the appropriate tools for the job. They start by cutting in around the edges of the room with a brush, and then roll the paint onto the walls in a "W" or "V" pattern.

5 Drying: Once the paint has been applied, it needs time to dry. Professional painters will ensure that the room is well-ventilated to help the paint dry faster.

6 Inspection: After the paint has dried, the painters will inspect their work for any missed spots or imperfections.

7 Clean-up: Once the job is complete, the painters will remove their equipment, remove the drop cloths, and clean up any debris or mess created during the job.

Keep in mind that the painting process may vary slightly depending on the specific job requirements and the painting contractor's techniques.