Inquiries about the best paint brand are frequent, yet in reality there are only a few brands. The major brands are Dulux, Taubmans, Wattyl and Resene. All major brands have several lines that vary in quality. If you are looking for the best quality paint, the question is not about the brand, but what line of brand to use. All of these brands have a trade line of paint that is quite cheap and will often not cover as well or withstand the elements as much as their premium line alternatives. Between premium and trade, there is also a professional line of paint. Professional is the middle ground in coverage and quality.
Paint typically accounts for only 10% of the entire cost of the painting project. As it is not a significant factor of the final price, you should insist that the painting company use a premium paint line from a major brand. Often painting companies will say that they only use Dulux but then use the cheapest trade line, this will affect the overall finish and lifespan of the paint job.