All About Green Paints and Finishes
Green Paints and Finishes
Green paint, sometimes termed eco-paint or natural paint, is becoming a popular option for home decorating. The reason for choosing these paints over conventional ones is directly related to harmful VOCs (volatile organic compounds) found in conventional paints and decorative coatings. It has now been established that these compounds — which aid drying times and help with viscosity — can be harmful. Paint manufacturers have therefore been tasked with finding an alternative that still allows the paint to perform to product requirement. Usually, more natural raw materials, such as linseed oil, are used in paint production. In fact, many natural paints have been in existence for hundreds, if not thousands of years.
All paints contain a binder, pigment, solvent and sometimes a filler. Binders make up the main film-forming body of the paint, the pigment provides the color and the solvent essentially creates the paint's liquidity. Sometimes fillers are added to further thicken the mixture and increase its volume. With natural paints, it is straightforward to identify these different components as they are all naturally occurring — there are no synthetic parts. The following table provides information about the ingredients of natural paints — there are many variations on each type.
Making Your Own Natural Paint
It is possible to produce any of the paints shown in the table below, and there are numerous "recipe books" available, all offering different ideas on how to mix the perfect paint.
When making your own paints, the main concern is to produce the correct quantity for the job ahead — it is impossible to match colors so you won't be able to make a supplementary batch. The second problem can be with sourcing ingredients, as natural paints are not mainstream. You will need to source specialist local suppliers — a process that is far simpler than it once was thanks to the Internet.
Lime Wash Paint
- Binder: Lime putty, non-hydraulic bagged lime or hydraulic lime
- Solvent: Usually water, but some have a small oil content (typically linseed oil), particularly with external applications.
- Filler: Not required in pure lime wash.
A recommended system would be 3 to 4 coats for use indoors and 4 to 5 coats for outside applications. Must be applied to a porous surface (not on top of other finishes). With casein lime wash, casein (derived from milk curd) is also added for greater adhesion.
Distemper (Milk Paint and Cheese Paint Derivatives)
- Binder: Soft animal glue, casein (derived from milk curd) or natural oils
- Solvent: Water, linseed oil
- Filler: Powdered chalk
A small amount of linseed oil is added, but the product is still water-based. While many milk paints only use the curd, more traditional types would simply mix skimmed milk directly with hydrated lime and pigment. Oil-bound distemper may contain borax—an emulsifier that increases durability. For interior use only.
- Binder: Flour (not always used in clay paint)
- Solvent: Water
- Filler: Clay
Clay often provides the color, although further pigments may also be added.
Natural Oil Paint
- Binder: Natural oils such as raw linseed oil
- Solvent: Natural oils such as citrus oil
- Filler: Not required
Natural oil paints have good all-around application, both inside and out.
Egg Tempura Paint
- Binder: Egg yolk or white
- Solvent: Water
- Filler: None used
Not normally practical for large-scale work, but is extremely hardwearing and can be effective for the detailing in moldings.
Natural pigments (not listed above) come from many different sources. Organic pigments can be derived from flowers and berries (although these tend to fade with light). More stable finishes are provided by natural earth pigments, such as ochre and umber. Most come in powder form, so precautions may be required to avoid inhalation of the powder while mixing.
Copyright 2009 Dorling Kindersley Limited
Text copyright 2009 Julian Cassell and Peter Parham