Natural paint basics
- See also Natural paint, for a topic overview.
Main Ingredients of Paint
The binder is the main body of the paint, holds the paint together (Innes, 1997) and carries the pigment (Bacon, 1975). The choice of a binder depends on how much paint you need and the surface to be coated. Natural binders that can be used are chalk, lime, casein (non-fat milk curds), animal or vegetable glues, and oil. Slaked chalk, also called whiting, makes a paint called distemper used for interior walls and ceilings. Lime has antibacterial qualities and is used for interior or exterior walls. Casein is the binder for milk paints; it is used for interior walls and for fine arts. Animal glues and vegetable glues make chalky paint and are usually used in fine arts. Oil is used for woodwork paint and fine art (Innes, 1997).
The pigment is responsible for the color of the paint. They can be found throughout nature in clays, herbs, nuts, berries, barks, carbon, charcoal, and soot. They are ground down into powder and usually boiled several times in water to remove impurities (Bacon, 1975).
Solvents are the fluid component of the paint. Solvents add transparency, extend drying time, and are used for cleaning and wiping away mistakes. Water is used as a solvent for distemper, lime wash, casein, and beer and vinegar glazes (Innes, 1997). Natural turpentine (made from tree sap) and citrus peel are used as solvents with oil binders (Steen, 2006).
Fillers reinforce the binder and give the paint texture and a thicker consistency. Chalk, talcum, marble and clay are all common filler materials (Steen, 2006).
All four main ingredients have synthetic counterparts. Most of the synthetic ingredients contain volatile organic chemicals (VOCs). A Johns Hopkins University study found that more than 300 toxic chemicals and 150 carcinogens may be present in paint. The USEPA has estimated that nationally, VOC emissions from architectural paints and coatings exceed 11 billion pounds each year. A safer choice is making your own paint at home from natural ingredients (Dadd, 1997).
Planning and Prep
When making your own paint, there are planning techniques and prep work that are essential to ensuring a good product and project. Allow plenty of time for experimenting. It takes time to get proportions and tones exactly right. Work out how much paint or glaze you will need because it is difficult to remix exact shades or consistencies. The amount of paint will depend on the surface area, absorbency of the surface and thickness of paint. Make sure to test paint. Write down recipes, ingredients, and proportions in a detailed record so you can replicate paints (Innes, 1997). Follow recipes faithfully when starting out. Proportions of ingredients are the most important; an incorrect ratio may reduce the ability to adhere to a surface, durability, and quality (Bacon, 1975). Mixing order is also important (Innes, 1997).
Brushes and Tools
The most important tool for painting are your brushes. A good brush is essential in application of paints. Also make sure to have the required brush for the kind of paint, surface, and application technique. A good brush is well worth the investment. Fitches are invaluable for mixing paints and glazes. Their densely packed heads of long stiff bristles are perfect for breaking up dry ingredients. Tools include jars, buckets, rags, containers, rollers, sponges, drop cloths, etc. (Innes, 1997).
Types of Paint
Water based paints are the best natural and environmental choice for solvent. The two top water-based paints are distemper and lime wash. Distemper is made of chalk, rabbit-skin glue, water, and pigment. This paint is very dense, goes best with pastels, and has a powdery finish. Its disadvantage is that it is not washable. Lime wash on the other hand is washable. It is made from lime putty, water, and pigment. It has antibacterial properties, is durable, and ages well. Casein can also be added to increase durability. Both paints leave a chalky, matte finish and allow walls to breath (Innes, 1997).
Oil paints are usually made of animal or vegetable oil, pigment, driers and/or resins, and white spirit solvent. A variety of oils can be used but the most common is raw linseed oil from the seeds of the flax plant. Advantages of using oil paint include flexibility, durability, rich and velvet texture. Disadvantages are ingredients can be flammable or toxic, and the room must be well ventilated. (Innes, 1997)
Flour paint is one of the most versatile paint types and can be used inside or outside, on wood, stone, drywall, wallpaper, earthen and gypsum plaster, masonry and to cover existing painted surfaces. This paint is very thick and can destroy brushes, but the recipe can be tweaked a little to achieve different textures. Flour paint typically consists of water, flour, colored clay and more uncolored clay filler (Steen, 2006).
Egg Tempera can be used inside or outside and can last for over 20 years. This paint dries in about an hour to a glossy finish. It consists of egg (white and yolk), boiled linseed oil, water, and pigment (Homemade Paint).
Casein paint is made from milk curds which can be purchased in powered form, but are also simple to make. The recipe is very specific but casein paint lasts a long time, is fungi resistant and compostable. Casein paint can be used inside or outside, on wood, stone, drywall, wallpaper, earthen plaster, masonry and to cover existing painted surfaces. Casein paint consists of nonfat milk, lime, water, filler and a pigment (Steen, 2006).
Disadvantages of Natural Paint
Natural Paint tends to be 20 to 80 percent more expensive than petroleum based paint. Whether purchased ready to use or made by the user, natural paints are less popular because they are more difficult to use. The demand for natural paint is lower so it is more expensive than less healthy alternatives (Pennock, 2005).
While the ingredients for making natural paints are easily accessible; many paint stores do not carry pre-made natural paint (Pennock, 2005). It is however possible to order pre-made natural paints over the internet.
Some natural paints that are sold ready to use actually require some “assembly” in that the pigments may need to be added and homemade paint can take more than two days to make. The consistency of the paint can affect the amount of time required to apply it to a surface (Steen, 2006). Some natural paints will need to be applied in multiple coats to achieve the correct color; 24-48 hours is required to allow previous coats to dry before a new coat is applied (Abdalla, 2005 and Steen, 2006). Natural paints take longer to dry than petroleum based paints (Abdalla, 2005).
Color and Consistency
Consistency is especially difficult to achieve when using homemade natural paints. It is advisable to make a large batch of paint in order to keep color and texture uniform (Steen, 2006). The color possibilities are limited unless synthetic pigments are added (Abdalla, 2005).
Advantages of Natural Paint
Natural paints are derived from organic materials and contain no synthetic ingredients. Due to their organic nature they are compostable and some are edible. Natural paints also contain low or no VOCs so they are healthier (Pennock, 2005).
A good paint breathes and allows the wall to breath. Breathable paint allows the wall to let moisture evaporate out. The great advantage of breathable paint is that it reduces the build up of moisture in a room that can be a major source of health problems. Many modern acrylic paints trap moisture in the walls and also impede the movement of heat between the room air and the wall (Roaf, 2001).
Homemade paint is one way to achieve a specific color or texture (Pennock, 2005). By using pigments from local surroundings one can create colors that match the immediate environment. Also many colors that are not sold in the stores can be made at home. Many different textures can be achieved by adding sand, mica, straw, etc. (Abdalla, 2005).
Natural paints can be made from renewable, abundant resources. They also require less energy to produce (Abdalla, 2005).
References and Footnotes
Abdalla, M., (2005). “Natural house paints…good enough to eat.” Ecologist Online, 1/5/2005 http://www.theecologist.org/archive_detail.asp?content_id=562 [accessed 2/3/2007].
Bacon, Richard M. The Forgotten Arts: Book Two. Dublin, NH: Yankee Inc., 1975.
Dadd, Debra Lynn. Home Safe Home. New York: Putnam, 1997. “Homemade Paint.” The Raadvad Centre. http://www.ibiblio.org/london/rural-skills/homemade/homemade-paint [accessed 1/31/2007].
Innes, Jocaste. Around the House Paint Recipes. Boston: Bulfinch P, 1997.
Pennock, A., (2005). “Selecting Healthy and Environmentally Sound Paints.” Green Home Guide, 8/9/2005 http://southatlantic.greenhomeguide.com/index.php/knowhow/entry/750/ [accessed 2/2/2007].
Roaf, Sue. Ecohouse: A Design Guide. Woburn, MA: Architectural Press, 2001.
Steen, B., (2006). “Make Safe, Natural Paint.” Mother Earth News (218), http://www.motherearthnews.com/DIY/2006-10-01/Make_Safe_Natural_Paint.aspx [accessed 2/3/2007].