Designing a Silhouette Puzzle

Since the first time I played with Question du Lapin, I was fascinated by Silhouette Puzzles.
Therefore I wanted to develop some silhouette Puzzles myself.

Puzzles, which consist of discs (usually 5) are referred to as silhouette puzzles.
Thereby each puzzle disc shows the shape of an object, which is cut out of the disc.
If the puzzle discs are put on top of each other in the right way,
then the silhouette of another object (intersected silhouette) becomes visible.

Each silhouette has some edge sections in common with the intersected silhouette.
Therefore the best strategy is to choose first the intersected silhouette
and then invent the other silhouettes.

Following points have to be considered when inventing or choosing the intersected silhouette:

The more re-entrant angle the intersected silhouette has ,
the bigger the challenge is to find further silhouettes.

The intersected silhouette should have approximately the shape of a circle or a square.
A silhouette like a circle or a square has the advantage for the designer
that it is much easier to find further silhouettes.
Whereas in case of an elongated silhouette, the solution can be guessed in most cases
and the game looses its excitement.

In addition the intersected silhouette should have no complicated edges,
straight lines and distinctive indentations and few curves.
You should always bear in mind that you have to build the complete edge with a few discs.

As I have difficulties to find a motiv for the intersected silhouette,
it is very helpful to search for pictures, especially for silhouettes,
in diverse picture search machines.

For my intersected silhouettes I prefer shapes,
where a part of the edge triggers associations with further simple figures.
(When you search for a silhouette, you should not worry if it is copyright protected or not.
The intersected silhouette will undergo many adaptations until the puzzle will be finished.
Therefore it will not keep its original shape.)

Small, superfluous details of the intersected silhouette should be removed,
the intersected silhouette should be simplified so that only the relevant details are recognizable.

After the shape of the intersected silhouette is set,
a paper disc should be made with the intersected silhouette in its center.
The paper disc helps to quickly estimate if the silhouette fits or if it is too big.
My experience is that the paper disc should be twice as long as the intersected silhouette.
To be continued.