What's The Difference Between Water-Based Or Oil-Based Paints?
Water-based products are quick-drying, easy to use and emit very little odour. They are also environmentally-friendly and often non-yellowing, plus they're easier to clean and the brushes will wash easily in water. However, although faster drying, they can have poorer flow properties. It is often possible to apply more than one coat in a day, but brush marks are more difficult to eliminate. Paints with a water base are often not as hard or durable as those with an oil base although they are rapidly improving all the time.
Solvent (or oil-based) products take much longer than water-based products to dry and can have a very strong 'chemical' smell. They have high VOCs (volatile organic compounds) which can contribute to pollution and can sometimes yellow with age. Plus solvent-based paints do need to be cleaned from the brush with white spirit. These types of paints need to dry overnight before further coats, but the marks left by the brush are distinctly less noticeable as the paint levels out.
It can be said both formulas have their pros and cons, but for anyone concerned about VOC levels, under an EU law which came into effect in January 2007, every single paint manufacturer must mention the level of VOC contained in their paint on the packaging. Plus from January 2008, in a further bid to keep harmful levels down, the same EU legislation has detailed acceptable levels of VOC, and has outlawed the sale of all non-compliant products.