Tech Talk #31: Why did my pigment change colour?

So, why do cosmetic tattoo pigments change colour?!?

Cosmetic tattoos are usually on the face and subject to UV exposure, which causes photodegradation (i.e., pigment fading!). You get instant photodegradation in laser tattoo removal.

The Blue Wool Scale, developed in America, measures the lightfastness of colourants. Through a process of controlled testing, the Blue Wool Scale (BWS) measures the amount of photodegradation of a colourant in sunlight for three-months.

A BWS rating between 0 and 8 is established where zero indicates extremely poor colour fastness. Eight indicates no alteration from the original colour and excellent lightfastness.

In Australia, the sun is intense and pigment photodegradation may be quite rapid, depending on an individual’s lifestyle and sun protection habits. Pigment lightfastness is therefore very important. Inorganic pigments typically fade faster than organic pigments (but not always).

The colourants in organic / inorganic mixtures (e.g., “fusion”, “hybrid”) need to be carefully balanced in terms of colourant lightfastness, otherwise fading will also cause colour change. Here are a couple of examples of common pigment ingredients that don’t follow the rule “inorganic fades faster than organic”:

• Iron oxide black (inorganic), CI 77499: BWS score is 8 (best fade resistance).
• Red 57 (organic), CI 15850: BMS score is 5 (moderately fade resistant).

Cosmetic tattooing or ‘semi-permanent makeup’ is designed to fade, technique and depth are one part of the puzzle. There is a lot that goes into making a pigment that fades just right.

P.S. Be careful if you are checking. There is another American standard (ASTM) which rates lightfastness form I to V, but that’s high to low! (i.e., opposite way round).

This article has been written in partnership with Registered Training Organisation, THink Aesthetics (RTO 45188).

The content included is a short adapted extract from the unit SHBBCOS002 the colour theory and pigments unit from THink Aesthetics' Diploma of Cosmetic Tattooing.

Stand out from the crowd. Become a diploma-qualified cosmetic tattooist - your pathway to unique knowledge and insights.

Learn more about the Diploma and start your higher education journey today.