Painting a faux Venetian plaster is a simple but artistic technique. If your tastes or color choices change after using this technique, you can sand over and start anew. The key to Venetian art is dual: (a) The more layers you apply, the deeper the look you will create and (b) the more pressure you place on your spatula in the final step, the greater degree of burnish you will achieve.
Step 1 - Prepare the Colors for Your Faux Venetian Plaster
Pour two or three of your paint colors into one aluminum pan or container. Pour the remaining paint colors into the other aluminum pan. Each of the colors should be separate, not bleeding into one another.
Step 2 – Start Painting the Background Layer of Your Faux Venetian Plaster
You should keep the steel spatula clean as you work. If dried paint or plaster accumulates on your spatula, you can scratch or mark up the surface of your work.
You may practice the technique on a board first, if you wish. If you feel confident, you may start painting directly on the wall.
Select one color, and dipping your trowel or spatula into that color, paint approximately a quarter of the wall. Work up from the bottom. Wipe the trowel.
Step 3 - Paint with the Second Color
Select a second color. Starting from the top of the wall, apply the paint about a quarter of the way down. Do not wipe the trowel.
Step 4 – Use the Third and Fourth Colors
Dip the trowel into a third color and layer it with the fourth so that there are two colors on the trowel. Starting near the top of the wall, paint the entire wall this time, so that you overlap the previous shades.
Step 5 – Continue Painting
Finish your application by continuing to smear your trowel with progressively darker colors. Always choose two at a time and, working towards the bottom of the wall, continue painting until you connect with your original layer of paint.
Step 6 – Evaluate and Dry
After you have painted the entire wall, step back and evaluate the result. Let your work dry for 1 to 4 hours until the wall shows a matte finish. You can always add more tones and highlights later, if you desire.
Step 7 – Apply the Venetian Plaster
Fill in ragged spaces with Venetian plaster. Smooth it with your spatula as you apply it. Even out the higher and lower areas until the wall is straight. Leave it to dry as before.
Step 8 – Polish the Faux Venetian Plaster
Apply three or four more coats, if you wish, according to the amount of texture or depth you desire. Rub the flat of the spatula against the wall in circular motions. This technique will lightly polish the surface of the wall. You can use the sandpaper for additional sheen.
If you are unhappy with particular parts of your work, you can always sand them over and repaint.