The vast majority of the technologies we use rely on a few materials only: silicon for electronic technology, steel for construction, plus a few functional materials. We polished those technologies extremely well, but, at the same time we became the slaves of those materials. At the same time we would strongly benefit if we could design materials according to our needs. Graphene is the first two-dimensional material with a number of unique properties. It also opened a floodgate of experiments on many other 2D atomic crystals. The resulting pool of 2D crystals is huge, and they cover a massive range of properties. Furthermore, we can bring those one-atom thick crystals together and start to create artificial materials with predetermined properties: materials on demand.