Watercolor painting is a versatile and refined artistic expression which can be appreciated and practiced by novices as well as professionals. Fundamental to this creative medium are watercolor pens, ...

An ink that changes colour when exposed to light, like an octopus does to match its surroundings, could one day be used for automatic camouflage. Most colour-changing inks and materials use chemical ...

The ink mimics one one of the special characteristics octopuses are known for Scientists at a university in Hong Kong have created a new type of ink which mimics a special characteristic made famous ...