Plaster was common for covering walls in the 19th Century, but with the advent of drywall, plaster fell by the wayside, since it was costlier and took longer to apply. However, with many homeowners looking to recreate the look of plaster walls, the art of creating faux Venetian plaster finishes grows in popularity.
You can buy fake Venetian plaster or hire a trained professional to finish your walls with real Venetian plaster. Some decorative painters train in Italy, but many take classes in the United States.
To create that look yourself, you'll find lots of help on the Internet or in a growing number of books. Do your initial experimenting on a test panel and not on your walls. That way, you can make mistakes without having to clean them up and start all over.
Start by using a textured paint with a consistency slightly thinner than joint compound. It's available at most good hardware centers, since it's commonly used to hide wall and ceiling imperfections and cracks.
Holding a trowel like those used to apply cement to the curved surfaces of swimming pools, apply the textured paint. The larger the trowel, the more surface you can cover with each stroke. Distribute the paint fairly evenly. You can go back later to achieve the texture you're looking for. Hold the trowel at about 45 degrees for the first pass, then flatten it out a little to create more texture.
Let that coat dry for about twenty-four hours before moving to the second step, which is applying paint to your textured surface. A satin finish works best.
Let that coat dry for at least an hour before applying the top coat, a water-based glazing liquid, with a medium nap roller. A glazing medium, tinted to your desired color, works better than watered-down paint, because you're going to go back immediately after you've finished and take most of it off again, and you would not be able to do that with watered-down paint. It dries too fast.
Once the glazing liquid has been applied, use a rag towel to begin removing it, using a circular motion. Go over the surface, allowing the glaze to collect in the low spots in your textured paint, until you no longer see any swipe marks. do not press down too hard and ruin your textured surface, and do not worry about mistakes, because you're making them BEFORE you tackle your walls.
Let the surface dry for about a week. It will have the look and feel of plaster, adding class and warmth to your room – at a fraction of the cost of real plaster work.