In modern day, we utilize the fresco method of painting to offer a room a soft, warm glow. This finish is achieved by painting on "still-wet" plaster. What this means is: the plaster is put up on the wall wet. This initial stage is when we paint the background of the mural. This stage of the fresco enables us to utilize approximately six to eight hours for laying in the color on the "still-wet" plaster. Using a semi-dry brush or a rag, we paint in the background. If using the traditional method of a brush, utilize some lime and mix it with the pigment establishing enough body for modeling. This method of mixing pigment and lime is called verdaccio.
After you have painted in the background using verdaccio we then paint our image using many strokes of brush and many coats of glaze to build up our color; rendering with glaze. By using this method of painting, we are not over saturating the image but sustaining the softness of the fresco.
Towards the day's end, you will realize the plaster has begun to dry and when you apply a brush stroke, you must be delicate. At this point in time, this could be the most rewarding time of rendering your mural. The plaster is thirsty and you must change your method of painting. By using a more watery medium and watercolor brushes, you will find yourself more apt in detailing your images. Be careful not to disturb your ground work. If you happen to be heavy of hand and expose white spots, stop painting. A long ago used remedy to "fix" the pulled ground is to mix sugar water and milk and paint into the limed plaster.
Once the plaster dries, your fresco is permanent for the life of the wall.
Now for the worst part of any decorative painter's reality: The REPAIR:
The fresco will take approximately four weeks to completely cure. In some climates, this may be longer. DO NOT begin any touch-ups or repairs prior to a minimum of four weeks.
In order to touch-up or repair a fresco, we can utilize a few mediums.
Wax ammonia-or cera colla...paint by stippling onto the area requiring help. I will offer the recipe at the end of this blog.
Use Zinc white for white colors.
Cera colla: I suggest you use a diluted industrial strength ammonia. Dilute the ammonia with distilled water. 95% water and 5% ammonia is then heated just prior to boil. Melt an equal amount of wax per volume. (Bees Wax). Pour the heated ammonia/water mixture into the melted bees wax stirring constantly until cooled. This mixture will effervesce and expand to ten times. Stir until the reaction subsides and remove from heat. Keep stirring until cooler and creamy with the texture of whipped cream. This consistency is easy for storage and may be diluted with water when prepping for painting.
In order to paint with cera colla, allocate the amount of medium desired from storage, store the remaining mixture. Add dry crushed pigment to the cera colla and water mixing for desired consistency.
The Egyptians used this method on their walls and some hieroglyphs. This medium, once dried, can be buffed and offer a soft warm glow.
So....you have been given a true artist and old master method of painting a fresco. Keep in mind, this method of painting requires stamina. This isn't a painting of which you can begin and come back to in a couple of days. Once the plaster is put up on the wall, you are facing a marathon of painting....anywhere from 12 to 22 hours depending on how detailed your mural. Enjoy and happy creating!