Matching Specified Colour

As a professional painter and decorator you may be required to colour match new and existing painting finishes. This will include planning and preparation for the work, matching of paint colour to a specified sample and completion of clean-up activities.

The following playlist of videos has been put together to assist you in gaining the required knowledge to match a specified colour.

Every paint manufacturer makes multiple bases into which tint is added. What is common to all is that the bases have decreasingly less white pigment in the "deeper" bases. If you paint with one of these bases without tint, you will get an extremely poor covering paint. A "deep" base paint will have literally no white pigment in it, however, acrylic paints look white in their wet state but dry clear. If you should paint with a deep base without tint, you are essentially putting on a coat of acrylic varnish.

A pure white tint base will have the full compliment of white pigment in it, but its coverage will be somewhat lacking. Even a few drops of raw umber or lampblack will dramatically increase its coverage.

Pigment does increase the protective value of coatings. A solid hide exterior stain will give far superior protection to wood over that of a semi-transparent stain because the higher concentration of pigment blocks the sun's UV rays.
It is important that you identify the correct paint base for the colour you wish to tint. If too much colourant is added to paint the paint will fail to perform properly, and may not dry. You can check the paint base by looking at the side of the can. On a colour chart the paint base is usually indicated by a code such as ‘B’ for ‘Bright, ‘A’ for ‘accent’, ‘W’ for White’, ‘D’ for ‘deep’, etc

Colourants

Universal colorants are materials containing a colour pigment dispersed in a blend of surfactants and a liquid (most often a glycol). In Australia it is common to refer to them as ‘tinters’, or ‘stainers’.

Paints are generally available as white, tint, and deep and accent bases that can be tinted to various shades and depths by the use of liquid colorants. The level of opaque pigment (in most cases titanium dioxide) is varied to balance the degree of hue (lightness darkness). The maximum amount of colorant that is added to each base is dictated by the final colour required, type and opacity of the particular colorant, and the level of opaque pigment in the base.

Many paint manufacturers only supply white, tint and accent bases in their paint lines. This assists in managing inventories and stock in the warehouse and stores.

If too much colourant is used, properties such as curing time, early and total water resistance, abrasion resistance, resistance to cleaners, burnishing (polishing) and uniformity, are affected negatively.

Exterior paints, containing high levels of universal colorants, can be prone to 'wash-out' from dew or rain for longer periods of time than 'non tints' or low level tints. Another unique problem that can arise is the appearance of surfactant bleed, which appears as a clear or yellowish material on the surface of the paint and can run down onto adjoining surfaces. Although waterborne coatings show the most problems, alkyd types can also be affected. Alkyds most often show lowered gloss levels, and some softness in the film for longer than normal.

Method for Matching Colours

Taking into account all the previous topics, we can now summarise how to match specified colour:

  1. Identify the colour to be matched. Are there any relevant standards or heritage considerations?
  2. Identify the appropriate type of paint. Eg. Acrylic or solvent?
  3. Identify the sheen level
  4. Establish the correct paint base
  5. Identify the hue (colour family)
  6. Select the necessary colourants
  7. Identify the value
  8. Create a sample of the colour by adding the colourants to the proportion needed, using formulas or by eye, mixing thoroughly at each stage. Record the amounts for future reference
  9. Test the sample and allow to dry. Colours may darken or lighten after drying depending on the type of paint. You could use a heat-gun to speed up the process
  10. Adjust as needed, allowing for tint or shade.

The best way to learn is by experience! There is no short-cut to accurate colour matching. It can be time-consuming, but is still an essential skill to have.


Tip: Many male painters suffer from colour eyesight deficiency. This common problem means they can’t see the full range of colours as women can. It might only affect them when matching one hue. For example, they may not see green as intensely as women. If you suspect you have this problem, (93% of men have some colour deficiency), also check your colour match with a female painter or your client.