As a subject for paintings, windows have been a staple of art for centuries. The attraction is no doubt obvious enough. A room, including a studio has a window, through which can be seen the outside world. A window can be preceded by what is inside the room and followed by what is outside. Themes are present without the need for models. Moreover, the contrast between the inner world of the room and life in the world outside offers enormous variety for an artist. Matisse is perhaps the supreme example of one who utilized the window concept in his work, but there are myriads of others.
In Petrescu's art, the window, either as a simple window or as a group with a balcony, or sometimes a wall of windows in a large house, has been a recurring subject. He paints them as often now as he did decades ago. They exist in all the styles and techniques that he has used. They are on the whole painted relatively realistically compared with most of his other works but they include highly abstract paintings. They have used all his techniques, including collage and gold leaf.
There is one aspect of Petrescu's windows that is different from most artists' use of the subject. For them, the window is normally seen from inside looking out and the subject shows what is outside, even if the major element may be inside. Petrescu's windows, with a very few exceptions, are seen from the outside and rarely can one see inside the room behind the window. At most there may be a suggestion of something on the window sill, or curtains. It is difficult to know why this style developed. Perhaps the fact that his second-floor studio in Bucharest is small and has its only window high in the wall, providing light but no view had an influence. Perhaps it is a desire to paint the separation between the visible world outside and the unknown world that exists in the room inside. This thought is suggested by a 1965 work entitled "Empty Windows" (UTT 2013/150). It is a surrealistic work, unusual for the artist, done in black ink with rubber stamps and brush. The composition, 13 by 11 inches, consists of small windows, as if in a large apartment house, most of them closed by wooden shutters, a few drawn curtains. On the walls a number of owls with bright staring eyes, all of them only partly visible on the black background of the walls of the house. The shuttered windows and the menacing owls present a particularly sombre and gloomy scene relative to most of Petrescu's work. The "entombment" series are certainly rather sad works, but the entombment presages the resurrection on Easter Sunday and they have nothing of the gloom of this "window" work.
However, in most ways, this "Empty Windows" is not typical of most of the series. Unlike the despairing character of "Empty Windows", Most other of the series are bright, cheerful works. They are windows with the sun shining on them. There is frequently a playfulness in the works, particularly the more abstract examples, where the basic window design is little more than a frame in which to execute paint or collage elements that have little to do with what an actual window looks like.
Collage has been an important part of the windows theme. The incorporation of collage gave a significant extension to the windows series. Petrescu is not a realist painter who could endlessly repeat variations of actual windows. Without the variety that collage offered to him, his window series would probably have been much smaller than it has in fact been. Collage provides an abstract element to the series that has permitted a great variety within what is, after all, a limited subject. For all that, he still paints "windows" from time to time that have no collage, which is perhaps an indication of the attraction that the theme has for him.