using biodegradable plastic or paste.
I use a rapid prototyping fdm technology machine and open hardware RepRap Prusa, which is a very interesting project because you can built your own printer. I did a workshop at the CIM Centre in Barcelona. I also use free software that you can find on the web .
 3d file, preferably .stl
 From almost two dimensions objects like my card, to objects with a maximum volumen of 190x 180x 120mm each item. Nevertheless I always recommend you to do it in separate parts
 Slic3r, Pronterface and Marlin
 Chocolate, pastry, icing sugar, from the Universal Paste Extruder