Thick paint techniques, also known as impasto painting, result in a textured surface oftentimes appearing three-dimensional. Admirers of impasto often look for visible brush strokes sweeping through the paint, which are sometimes considered more desirable than the subject of the painting. Artists use impasto for its expressive qualities and vivid, saturated colors. Vincent Van Gogh is famous for his impasto technique which added movement and emotion to his canvases. Drying times for thick paint vary. If a drying agent is not used, thick oil paint may take months and sometimes up to years to completely dry.
Tools To Apply Thick Paint
A trademark of impasto style painting is seeing brush strokes creating texture in thick paint. Experiment with both soft and stiff bristle brushes to see their varying results Palette knives, which come many sizes and shapes, are the most convenient way to smear on paint, similar to icing a cake, or blot chunks of paint onto the canvas surface for bright blasts of color. If the thickened paint has more liquid attributes it can be poured or dripped onto a canvas.
Acrylic Thickening Mediums
Acrylic paint has a number of thickening agents on the market. Liquitex “Liquithick Thickening Gel” is among the most popular. When this formula is added to acrylic paint in small amounts it will assume the characteristics of oil or encaustic paints (wax paintings). When used in large amounts with acrylic colors, this thickening gel will create a “cake” or sculptural consistency.
Golden brand has a wide variety of professional gels and pastes which range from pourable to moldable. They can extend paint, create texture, alter finishes and be used for thin layer glazing techniques. Each medium has its own instructions, though most can be mixed into paint using a palette knife and water. A couple of Golden thickeners can be used as paste for collage as well.
Many of the paste mediums can be applied prior to mixing paint, creating a surface which can then be painted over. For areas that will be painted over, try mixing a small amount of color into the paste mixture prior to applying as a primer. Then, if your brush or palette knife misses an area that may have formed a bubble or has a difficult recess area, there will already be color underneath. Creating a prime color can also function as an under color, allowing for a variety of glazing effects.
Oil Thickening Mediums
Adding sand or sawdust to oil paint is the most cost-effective way of thickening this material. Or try squeezing oil paint into a paper towel or newspaper, allowing the paper to absorb all excess oils. After the oil is removed through the paper, use the remaining paint as is or add stand oil (which is thicker in nature than the linseed oil already found in the paint) to help with flow.
A medium from Germany called LUKAS Painting Butter Impasto is also recommended for thick paint without cracking or wrinkling. It contains a drying agent and an alkyd resin base. When mixed with oil color, it produces a smooth buttery feel.
Zec Gel from Grumbacher is a colorless gel-like medium that shortens the drying time of thick paint. It is mixed by adding two parts Zec with one part oil color. The drying time for this mixture is four to six hours. Because of the very quick drying time, this medium may contribute to pigments darkening or becoming brittle over time.
Gamblin sells Galkyd Gel or “G-Gel”. This is an alkyd resin with a small amount of silica that comes in a gel material. It is good at retaining brush strokes and each layer can be built up to ¼ inch thick. This material can be layered several times for even thicker impasto effects. This product does not contain a drying agent, so it may take longer to dry than other gel mediums.
Liquin Impasto Medium by Windsor & Newton is a semi-gloss, non-yellowing and quick drying thickener that also retains brush strokes. Several oil painters have recommended this as a cost effective way to thicken their paints.