<these are the only two preproduction sketches that survive. They are both pencil drawings on animation paper and represent early thoughts at scene layouts.
Turning them into negatives like this reminds me of the economical way the pencil tests were shot in Prague at that time, on sound film, like in the old Hollywood days. The lower layers of the animation were always a bit hard to make out, being buried under several layers of paper. Even backlighting the artwork didn't make much impression on visibility.../>

<I had to make the whole film as a linetest before it could be submitted for completion funding. As a result the soundtrack was made after the animation was finished, which is the opposite of how most studios approach the process. The music was written by Angelo Michajlov,a Bulgarian composer who was out of political favour at the time and glad of the commision. The musicians were a group of players from the Czech Philharmonic Orchestra who regularly did animation work. The linetest was edited down into about 9*30-45 second loops and projected on a sound stage. The band had to keep on playing until they eventually managed to sync up to the picture.../>