Around the decade of the 1940s, Xul worked intensively on his new creations: Panchess, panlingua and probably his first ideas for a new type of theatre. Most of the pieces from the early part of the decade present a chromatic reduction –"Fiordo" [Fiord], "Valle hondo" [Deep Valley], "Muros y escaleras" [Walls and Staircases], "Ciudá y abismos" [City and Abysses]– that, at the moment of describing this technique, he defined as “drawings”, which in fact they are not. It is about temperas where he limits himself to working at depth, but they seem to give us the key to understanding the basis of his whole oeuvre: there is no painting without colour. It is also interesting to remark on the atmosphere he creates, the depth achieved through the use of blacks. In order to achieve that it is likely that he used stereoscopic views –which have the peculiarity of producing a tridimentional effect when looked at through a stereoscope– that he owned and that, without leaving his small studio, provided him with a wide repertory of foreign landscapes.