Question: What's your favourite colour ink you use?

Jess Wade answered on 19 Jun 2015:

Yves Klein Blue. It;s a super deep blue made by a french artist called yves klein. Once, I went to Morocco for my mum’s birthday and we visited the YVes Klein garden. The colours all come from something called a pigment, which changes the colour of the light when it hits off it. With most blue materials they absorb one colour of light and reflect the other, and that other colour is the one that comes in to our eyes.
A material I work with a lot is called phthalocyanine. It is a collection of copper, nitrogen and carbon atoms connected in a ring. It reflects a really beautiful blue colour. They use it as the ink for lots of things, like five pound notes!
The special blue in Yves Klein blue isn’t using a special ultramarine pigment, but instead a special mixture of materials that keeps all the molecules apart from one another. It means the blue is really pure. When lots of differnet molecules hit into each other, they don’t behave so well and reflect light differently. Lots of bands and authors write songs and books about the colour! Look it up!