Holography

I have decided to research holograms and how they are made simply because I dont know how they are made and I wanted to find out....
Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded. The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the recorded image (hologram) appear three dimensional.

This is the best video I could find to illustrate how you make a hologram:

Holovision uses an embossing process to create the holograms. First the hologram is made on a light sensitive resist plate. This is metalised and nickel copy made by electroforming (like chrome or silver plating). This copy is stamped into acrylic as a tiled pattern to form a recombined master shim. This is metalised and a final nickel embossing plate produced. The recombined master is analogous to a printing plate which is attached to a steel embossing roller and under heat and pressure embosses a relief structure into the polyester plastic. Adhesive is applied to the back and a release paper attached. Finally the holograms are die cut to size and wound onto rolls for either machine or hand application.

Mass production of holograms:

An existing hologram can be replicated, either in an optical way similar to holographic recording, or in the case of surface relief holograms, by embossing. Surface relief holograms are recorded in photoresists or photothermoplastics, and allow cheap mass reproduction. Such embossed holograms are now widely used, for instance as security features on credit cards or quality merchandise. 

The first step in the embossing process is to make a stamper by electrodeposition of nickel on the relief image recorded on the photoresist or photothermoplastic. When the nickel layer is thick enough, it is separated from the master hologram and mounted on a metal backing plate. The material used to make embossed copies consists of a polyester base film, a resin separation layer and a thermoplastic film constituting the holographic layer.

The embossing process can be carried out with a simple heated press. The bottom layer of the duplicating film (the thermoplastic layer) is heated above its softening point and pressed against the stamper so that it takes up its shape. This shape is retained when the film is cooled and removed from the press. In order to permit the viewing of embossed holograms in reflection, an additional reflecting layer of aluminum is usually added on the hologram recording layer.

It is possible to print holograms directly into steel using a sheet explosive charge to create the required surface relief.

^{Holograms in art:}

Early on artists saw the potential of holography as a medium and gained access to science laboratories to create their work. Holographic art is often the result of collaborations between scientists and artists, although some holographers would regard themselves as both an artist and scientist.

Salvador Dalí claimed to have been the first to employ holography artistically. He was certainly the first and best-known surrealist to do so.