“The word montage came to identify specifically the rapid, shock cutting that Eisenstein employed in his films. Its use survives to this day in the specially created ‘montage sequences’ inserted into Hollywood films to suggest, in a blur of double exposures, the rise to fame of an opera singer or, in brief model shots, the destruction of an airplane, a city or a planet” Arthur Knight 
When the avant-garde filmmakers collaged multiple images within a single frame, or ‘painted and scratched film, or revolted against the indexical identity of cinema in other ways’ , they were working against “normal” filmmaking procedures and the intended uses of film technology. (Film stock was not be designed to be painted on). Thus they operated on the periphery of commercial cinema not only aesthetically but also technically.
One general effect of the digital revolution is that avant-garde aesthetic strategies became ‘embedded in the commands and interface metaphors of computer software’.  In short, the avant-garde became materialised in a computer. The avant-garde strategy of collage re-emerged as a “cut and paste” command, the most basic operation one can perform on digital data.
The idea of painting on film became embedded in paint functions of film editing software. The avant-garde move to combine animation, printed texts and live action footage is repeated in the convergence of animation, title generation, paint, compositing and editing systems into single computer packages.
Finally, another move to combine a number of film images together within one frame (for instance, in Leger’s 1924 ‘Ballet Mechanique’ or in ‘A Man with a Movie Camera’ also become legitimized by technology, since all editing software, including Photoshop, Premiere, and After Effects, assumes that a digital image consists of a number of separate image layers.
All in all, what used to be exceptions for traditional cinema became the normal, intended techniques of digital filmmaking, ‘embedded in technology design itself.’
Painting on film can be seen in one of my favorite films directed by Jorge Grau ‘The Living Dead at Manchester Morgue’ 1974 which was filmed around Derbyshire, Manchester, Lancashire and Spain. In the film grab below which was filmed at Winnats Pass, Peak National Park, Derbyshire, you can clearly see the church has been painted onto the film negative to give an illusion the church is located there.
The church is actually St Michael and All Angels Church, School Lane, Hathersage, Hope Valley, Derbyshire and most of the film is based around Hathersage.
Being a film buff and a large collector of rare and out of print films, I could not write this blog without researching more on Soviet Russian film director and theorist, Sergei Eisenstein (1898 – 1948). Eisenstein is often cited as the revolutionary figure in the use of montage for films. Some of his most popular works include the silent films Strike (1925) and October 1927 (1927). The editing of his films is often connected to the earliest presence of montage elements in cinema. Early filmmakers cited him as the innovator in montage and met with Fritz Lang during the filming of Metropolis (1927) and his influence can be seen in the film.
Other movies which used film montage scenes and the most famous one being Orson Wells (1941) movie ‘Citizen Cane’, which used an impression of passing of time, in the scenes of the breakup of Citizen Kane marriage while sitting at the breakfast table at different stages in time in consecutive shots. While the characters get older, we also see a marked difference in their appearances and lack of interaction.
Viewing the artistic works of artist Remedios Varo, whose most famous work ‘Useless Science’ 1955 depicts a montage scene of science and dreams, I can’t help but think that this painting inspired Lang’s ‘Metropolis.’ The solitary figure sits on a stool wrapped in a black and white checked material turning a crank handle and the towers prove how film, art and photography inspires each other.
 Russett, Robert and Starr, Cecile Starr, 1976 ‘Experimental Animation’ New York: Van
Nostrand Reinhold Company pp. 117
 Stephen Kovats Stephen 1999 “Avant-Garde as Software,” iFrankfurt and New York: Campus Verlag pp 10