Mark out a square or rectangular area of the wall for the chalkboard with painter's tape or masking tape. Hold a level against the edges of the tape to ensure the tape is level and squared as desired.
Paint a primer onto the wall inside the taped-in borders. The tape prevents the primer from spreading to the rest of the wall and leaves behind a crisp edge to the chalkboard. Allow the primer to dry overnight.
Pour the chalkboard paint into a paint tray. Roll on one coat of chalkboard paint in top the primer, using a paint roller. Roll the paint on in one direction to create a smooth coat. Allow it to dry for two to four hours.
Add a second coat of chalkboard paint so the painted area is evenly coated with no visible streaking. Allow the second coat to dry overnight.
Peel the tape carefully from the wall. Use the chalkboard-painted area as you would a regular chalkboard.