Aspects of Paint Quality:
The key quality parameters of architectural paints are listed below followed by a brief discussion on each. Scroll down to read about any one.
- Appearance and Feel
- Hiding Power and Coverage
- Ease of application
- Environmental and Health impacts
Making paints durable takes an understanding of chemistry and additional cost.
Durability against the suns UV radiation, against the weather elements, against knocks and bumps, against temperature fluctuations that cause surfaces to expand and contract, against bacteria that feed on and weaken paint, against mildew and other biological activity and against the impact of a number of air and rain born pollutants are all essential.
Translated into paint characteristics, the paint needs to have a well formed (coalesced) film and high adhesion, must be flexible, tough but not brittle, colour-fast, water resistant, dirt resistant and must have components that are not sensitive to UV-radiation as well as agents that protect it from this radiation. A good degree of alkali durability is required for primers that are painted directly onto plasters or cement.
Paints for different applications require the various properties to differing degrees. Exterior Paints need high UV resistance and those that have this cost more. Generally Interior Paints should either have high scrub resistance (for cleaning and damage resistance) and/or be stain resistant. Good matt paints should be scrub resistant while good sheen paints should be stain resistant.
- More binder generally makes paint more durable. This can be measured by the PVC (pigment volumeconcentration). A lower PVC % means higher binder level.
- Binder type is critical. Some binders are sensitive to UV-radiation. Binder selection also influences toughness, hardness, brittleness and flexibility.
- More TiO2 (titanium dioxide) gives more UV resistance to white and lightly tinted paints. In deep colours the colourant should perform the same role.
- The numerous minor paint additives used can have a major impact on properties such as water resistance so their selection is important.
Appearance and Feel:
Make your correct choice up front. Get the correct degree of sheen. Matt and Low Sheen paints are trendier currently but when purchasing matt paint be sure to get one that is sufficiently durable. When selecting a colour you need to visualise the small colour sample over a large area which is not always that easy to do.
The final appearance can be very negatively influenced by small defects. A number of paint properties are influenced by flow (or rheology) of the paint and must be optimised in the paint formulation. These including flow and levelling (to reduce brush marks), sag (to prevent run down which leaves streaks) and drip and roller spatter (keeps you and your work area clean).
Sheen paints show up surface imperfections far more than matt paints.
For our 1050 colours see the "Colours" section of this web site.
Coverage and Hiding Power:
Does a little go a long way? Do you require extra coats of paint?
Hiding the substrate can be achieved by applying a thicker paint film or multiple coats but these require more paint and/or more effort. Paint with high opacity (hiding power of a certain film thickness) requires a lower coat thickness to high the substrate. The terms 'Coverage' and 'Hiding Power' are used quite loosely and interchangeably. Often the term coverage is used to describe a combination of Hiding Power and Spread Rate. The least paint is required when Hiding Power is good and Spread Rate is high. Spread Rate is measured by how many square meters can be painted with 1 litre of paint.
A required outcome of painting is often to hide the surface being covered. Single coat paints need to layer on thick enough and have high enough opacity to hide the surface with one coat. For durability it is normal to stipulate that two coats are required for exterior painting but poor paints may require three coats to give complete hiding of the surface.
In white paint, opacity / hiding power is derived mainly from light scattering. The degree of titanium dioxide (TiO2) is critical for high opacity. Finer extender particles and the use of synthetic pigments also assist. In darker colours, opacity is mainly derived from light absorption. The colouring pigments play a large role in ensuring that Hiding Power is good.
Ease of Application:
- Paint with a low brush drag slides on more easily reducing painting time. Our paints meet this requirement perfectly.
- Low drip, sag and spatter – it's a matter of chemistry. Cleaning up time and inconvenience can be greatly reduced. Numerous cheap paints give an enormous amount of roller spatter. All of our paints our formulated to give little or no spatter.
- Good flow characteristics reduce brush marks, improving final appearance.
- Painters will know about open time. A good open time allows the painter more time to "keep a wet edge" which improves final appearance and uniformity.
- And of course one coat less saves a lot of time and effort. Many of our products will usually only require a single coat.