Through his experiences with Wagner and the theatre, Fortuny became a lighting engineer, architect, inventor, director, and set designer. As a set designer, he wanted to create a more seamless way of transitioning from one scene to another other than flying out a backdrop and bringing in a new one. He began experimenting with light and different ways to do this in the attic of his palazzo in Italy. With his experimentation, he found that reflecting light off different surfaces could change the color, intensity and other properties of light. His 1904 treatise "Eclairage Scenique" ("Stage Lighting") describes the discovery that formed the basis of his indirect lighting technique. He concluded that, "... it is not the quantity but the quality of light that makes things visible and allows the pupil ... to open properly."