Interference & Chameleon Pigments

I am a total colour nerd/geek/who even knows what words mean these days anymore. Which leads to me being a nerd/geek on all things that make colour. That includes, the light spectrum (how we see colour) and pigments (how we recreate and use colours). Other topics include the anatomical requirements and limitations on how we and other living things perceive colour and how technology utilises the science of light and consequently, colour.

it's a rainbow!
(thanks Google... thanks Wikimedia... thanks svgtopng)

Lately, the topic of interest for *ME* has been the behaviour of interference & chameleon pigments. They can be seen in car finishes, acrylic paint mixes, plastic colouring, and nail polish (and colouring for everything else). Other words that have been used include "transforming", "duo-chrome", "multi-chrome", "iridescent" "flash colour" and "colour shifting".

(adding such an image makes me feel sad that I do not currently
have a decent vector program or a scanner for scribbles... I do have
a rubbish camera phone though!)

The tiny jpg'd-to-death text in the image (from Just Pigments) reads:

In the manufacturing of the Interference pigments, the TiO2 layer thickness is carefully selected and controlled to produce the desired color. In the case of Iridescent Pearl, the TiO2 is sufficiently thin, such that all wavelengths are reflected "in-phase", yielding a white reflectance. For Interference Gold, the thickness of the TiO2 layer results in the wavelengths representing yellow to be reflected "in-phase", yielding a bright gold at spectacular angles. The same principles pertain to Interference Green.

Firstly, I AM NOT A SCIENTIST. At least not in the professional or qualified sense. Which seems to be what a lot of people seem to only care about these days. However, I do have a keen interest in science... and I promise that I'm not an anti-vaxxer conspiracy theorist :(

Anywhooo... I definitely did do high school science and this *is* at the level of high school science so I feel confident to explain some of the science here.

TiO2 is Titanium Dioxide, it is commonly used as white pigment. So, basically, the white stuff. This is partly why most interference pigments appear whitish.

Mica is explained here by The Blue Bottle Tree far better than any attempt I can make. So basically, mica can be coloured AND can be mixed WITH pigments. They start off as separate materials though. Mica powders also tend to be less vibrant in intensity as a lot of pigments, so they are mixed to get a specified balance of shine and colour intensity.

Wavelengths, in-phase, reflected ie. "unneeded/unwanted" colours are absorbed (not seen) and the "required/desired" colour (wavelength) is reflected making the object appear as that colour. This is why interference pigments are usually shown on a dark background.

Have you heard of Unicorn Pee? Well, that's a whole 'nother post for another day! The short version is, Unicorn Pee or UP is an orange red that has shimmers from gold to green. So, it is a type of chameleon pigment. Basically, pee is usually yellow and so, UP appears to be from a very dehydrated unicorn, with an appearance of dark yellow-red that sparkles gold and green. The specific Unicorn Pee pigment (The New York Times, by Alice Gregory, March 12, 2014) that lacqueristas/lacquerheads go 'nanas for is of a specific particle size... or something...

Many pigment suppliers stock variations of both interference and chameleon pigments and most nail polish companies have released polishes utilising the fascinating effects of those pigments.

Transforming polish topcoats from Pretty Serious Cosmetics

MAC Studio Nail Transformation toppers

You can see the MAC toppers applied at beautygeeks by Karen Falcon (JUL 7, 2014 - MAC Transformations + MAC Studio Nail Lacquer + Swatches)

And then there are "iridescent" "flakies".
Iridescent meaning interference and/or chameleon, and flakies meaning flakes, little bits, small particles (but not microscopic small) etc they are basically just bigger flakes of the pigment than its powder form. They also do best on a dark background.

Iridescent flakies polish topcoats from Pretty Serious Cosmetics

Polishes are by Starrily but I have no idea what collections they came from or when they came out.

not active but still crazy useful

For a hobby focused resource, Polish & Pigments (franken polish research & information) is a brilliant reference treasure. Alas, it does not have a search bar and neither do I (sorry for the current plain-ness of this blog), so I must go through all the articles! (not really but eh)

Holographic and metallic, pigments and flakes are different topics for another day.