Heinecken (1931-2006) was a multi-media artist best known for his assemblage of found imagery.
Though his work appears to be done with film, he's not exactly a photo-collage artist; he used techniques that were quite a bit more analog (though I suppose film could be considered pretty analog these days!)
A note from the publisher of the collection about Heinecken's method: "The Recto/Verso photograms were made without the use of camera or film. A single page from a mass-circulation magazine was placed in direct contact with color photographic paper and exposed to light. The resulting image superimposes the visual and verbal information from the front and back of the magazine page. No collage, manipulation, or other handwork was employed."
The Recto/Verso portfolio is available through Vincent Borrelli, in case you happen to see it on my Christmas wish list.
I've been a fan of double-negative imagery ever since I had a faulty camera as a child. I received a pleasant surprise when my shots came back from the developer looking totally psychedelic.
(This post was originally posted on 04-20-11. I republished it because the MoMA is presenting a Heinecken exhibition right now, through September 07, 2014, titled Object Matter)