Well, anything is possible if you understand the way it works. Visible light is a tiny part of the entire electromagnetic spectrum, located somewhat in the middle, just above infrared radiation and just below ultraviolet radiation. Our eyes only detect wavelengths in this small part of the spectrum. A good way for you to test this is to get inside a small room, such as a bathroom or closet, one where you can close the door, and turn off the light. Depending upon how much light is leaking into your room, you won't be able to see much in your darkened room. But the objects in the room are still there; you can reach out and touch them, but you can't see them. So, to make something invisible, you would have to coat it with something that would allow minimal reflection of the visible light waves. A material that would hold onto all incoming visible light waves that would normally reflect off it and into our eyes, where the incoming light would be transferred into an electric nervous signal, and fed to our brain, which would interpret what our eyes are "seeing".