Designer Jeroen van Mechelen of studio JVM has created another great and eco-friendly room design. He has created the Hidden Line, a stylish and eco-friendly guest room made of cardboard. We already have seen various room designs made of cardboard, and this new creation of Jeroen van Mechelen is just another addition and a clear indication that more and more designers are now getting aware about the environments and they show it with their earth friendly designs. At first look, the room looks like the ones made of first hand wood. However, if you were to take a closer look at it, you will get to notice the beauty of the cardboard used.