#MARBLING – Part 3 Positive/Negative Method
May 23, 2014 Author Sydney Painters; bloomin
Following is part three of our marbling article;
There are two basic techniques used to imitate marble
- Overglazing – see article part 2
- Positive and Negative Methods
B. Positive/Negative Method
The negative method achieves a marble effect by removing sections of an applied medium to expose the colour underneath to give more depth.
The positive method involves the putting in of colour or veins to achieve a marble effect.
- Application of ground colour
- Application of background effects
- Application of marbling medium, veins and patterns etc
- Application of clear protective coatings
Note: Use of an oil vanish rather than a polyurethane varnish as there is a possibility that the polyurethane varnish dries too hard for the soft marbling mediums used, which could result in the cracking of the coatings.
Application of Veins
After the background effects have been completed, details such as the application of colour and the veining patterns are carried out.
The veins in marbles are produced when pigments from earths and minerals are washed into faults or cracks in the marble.
In marble itself, some veins emerge from the depths to become bold and obvious, whilst others retreat from the surface and dissolve into a cloudy background.
There are two methods of producing veins in marble, Positive and Negative Veining. Positive Veining is application of painted veins over the glaze medium and background effect. Negative Veining is the removal of colour in the shape of a vein to expose the background below.
A range of brushes can be used to apply veins using thin paint or coloured glazes. The brush should be held lightly by the tip of the handle and drawn across the surface, it may be rolled between the thumb and forefinger to produce veins varying in thickness (positive veining).
A goose feather can be used with thin paint or glaze to carry out positive veining or it can be dipped in solvent to remove paint or glaze producing negative veining. Negative veins may also be produced by using a rubber eraser with a chisel wedge point to remove coloured glaze. Crayons or pencils can also be used to produce veins when marbling in oil and water mediums.
Softening of Veins
Many of the veins which are applied may need to be softened or blended with the background.
A badger (watercolour) or hog hair softener (oil colour) or a clean lint free cloth can be used to soften the colour of veins while they are still wet. Stippling will also break up and soften any unwanted hard lines.
Direction of Veins
When applying veins to the work, the finished result will look more decorative if the principal veins are applied diagonally across the surface (approximately 45 degrees).
Take care not to develop pronounced curves when veining. Vary the thickness, change the direction slightly and break up the veins by softening or stippling.
For more information about Marbling or any Painting and Decorating tasks please Call Bloomin’Good Sydney Painters on 1800 204 145.