Personal Blog: Colour Matching and RAL Misconceptions

Colour Matching

Colour Matching

There is often a misconception that so long as a RAL code has been provided then the paint should provide perfect Colour Matching – as they say , “if it was that easy, everyone would be doing it”. There are many things to consider, one of the most important is that you will never get an exact match because you are trying to match different application methods under different conditions.

Why do we spray? Simply because the finish is the “closest” match you will get outside of a factory environment. That sounds straight forward, but there are more factors that should be considered. No two paint sprayers will get the same finish, so where possible, keep to the same sprayer. This is because they will have their spray units set differently i.e. more or less pressure or more or less paint flow, which would give different finishes.

If you spray a car it is a different practice where it is later covered with a Lacquer coat, which gives the shine and hides any paint blemishes. Most powder coat finishes are 30% gloss. However if the painter applies a coat too lightly it will create more of a matte finish. If they then apply the paint too heavy it will often run or create an orange peel effect on the surface.

Compound these hurdles with fluctuating temperatures, which also could affect the gloss level or finish. The painter then may need to apply fast thinners in winter to get the paint to dry quicker or slow thinners in the summer to slow the drying time down so that the paint does not cook. All of the time trying to achieve 30% gloss finish.

If working at height on a windy day, the fan (paint spray coming from nozzle) may get blown about resulting in an uneven finish or even striped effect. Now all of that is “IF” the paint suppliers can get a decent colour match in the first place!! So please keep this in mind while you inspect a painters work, they have invariably done battle with the elements to achieve the best possible result in colour matching for you.

Ian Hill

The Glass and Paint People