He just needed one stick to hold the sheet of cut out aluminum, and he was ready to paint . Then , something to cover the support stick like a rock, a bush, a pole or just another aluminum portion and make it invisible painting the background landscape.
Emilio Ruiz was very often asked to add some elements on a real location. It could be a castle, a church, a house o whatever. On his early years, he used the traditional glass shot technique. Which is very suitable for filming inside a studio, but going to location with a huge sheet of glass is not an easy task, not cheap either , for the low budget films he used to work at. He started to used a very simple method to avoid this problem; painting on a sheet of cut out metal, thin aluminum. Depending of the painted element size, he used one or two fastening points. Usually one vertical and another horizontal ( figure2) But sometimes the painted element was so small he could be attached with one single fixing (figure 1) During the sixties and seventies he became an expert on this kind of small tricks, and he got so much confidence that sometimes he does not even bother to hide the support with a foreground element (rock, bush, etc) and he just paste another aluminum strip and paint it with the background colors. With so many years of experience, Emilio Ruiz knew how far could he get with those tricks.
So, if you are watching a European coproduction on the sixties or seventies, and suspect something on the background could be a painting, if there is a pole, a rock or anything similar on the foreground, it is very probable you are watching an Emilio Ruiz "in-camera" miniature painting.
Talking about daring tricks, this is one if the boldest " in camera" paintings of Emilio Ruiz. For the film Special mission Lady Chaplin (1966, Alberto De Martino) He painted a building over a hill with an invisible vertical support in the middle of the frame.
Why I´m so sure? , well I have seen the film, and during a second the trick is exposed when a yellow car moves on the road that crosses the frame horizontally and goes behind the painting just for a second.
The film is on Youtube, so you can see the the trick at the beginning of the film during the title credits at 0: 36
Scherezade (1963, Pierre Gaspard-Huit)
A bullet for Rommel ( 1969, Leon Klimovsky)
They got only four real tanks and the director wanted a column of them. At the central part of the frame, there is a miniature cut out painting that hides a small structure with a miniature landscape with a road and small models of tanks moving down the path.
Kill them and come back alone (1969, Enzo Castellari)
Both views of that ruined church are foreground painted miniatures.
Eagles over London (1969, Enzo Castellari)
A reason to live a reason to die (1972, Tonino Valerii)
Zorro ( 1975, Duccio Tessari)
The inglorious Bastards (1978, Enzo Castellari)
There are many more, that´s just a glimpse of Emilio Ruiz´s art.