The black ink adds all the highlights and detail. The ink itself consists of two different properties, the pigment and the "vehicle." The vehicle is heated until it is runny and then the pigment ...

To understand how this works in highlighter pens, we can compare them to ordinary ballpoint pens. When light hits the ink of a blue pen, the ink reflects blue light and absorbs other colours ...

A research team analysed data from thousands of twins and found that people with tattoos were more likely to have skin and ...