The Surrealist technique that presses wet paint between two surfaces and then separates them is decalcomania.
In its Surrealist form, an artist spreads wet gouache or another fluid paint on a surface, presses paper, foil, glass, or another material against it, and then pulls the surfaces apart. The resulting irregular textures and branching patterns can suggest landscapes, creatures, or dreamlike forms. The artist may then develop the accidental marks into a finished image.
Óscar Domínguez adopted the technique in 1936, and Max Ernst also explored it. The process differs from frottage, which creates images by rubbing over textured objects, and grattage, which scrapes paint across a textured surface. Collage instead assembles and attaches separate materials. The broader word decalcomania also refers to transferring printed designs onto pottery or other surfaces, so the Surrealist usage is one specialized artistic application of a longer-established transfer process.