The star is named after its inventor, Friedrich Wilhelm August Fröbel (1782-1852). It was conceived as one of many activities for children in Kindergarten (nursery school), another invention of his.
This star is perhaps the most famous of his handicraft constructions, and the net has numerous descriptions of how to fold it, but I think this site would not be complete without one.
According to the wikipedia, it is also known asAdvent star, Danish star, German star, Nordic star, Pennsylvanian star, Polish star, Swedish star, and Christmas star in English.
[Note: Most steps are illustrated by more than one picture. The idea was that alternative views would help the viewer understand what's going on. Unfortunately, since 2006, this site has become greedy, and has clamped down on the free viewing of these alternative views. Now you have to pay to see them. Not exactly what I had in mind. They have also "edited" the title of this Instructable, as if I would not know what to call my own instructables. The title should be "Fröbelstern", nothing more, nothing less.]
Step 1: Cut Paper Strips
It really helps if their width does not wary too much along their length, so if you can get hold a roll of ticker-tape or some other type of pre-cut paper strips, go for it. An office cutting machine is a good option if you have to make your own.
Step 2: Fold
Step 3: Trim the Tips
(If you plan to fill a X-mas tree, this step should be possible to throw out once you get the hang of things.)
Step 4: Make the "base Knot"
If you pull the knot too tight, it will be hard to pass the strips through it later on.
(OK, the first picture just shows you how to fit the pieces together, ""the second'"" shows you the base knot in its tightened state.)
Step 5: "Extend" the Base Knot (folding)
Step 6: Extending the Base Knot (final Tuck)
Step 7: Adding Flat Points
The first method do without any pre-folding at all. You simply twist and tuck the appropriate strips in the fashion showed in the pictures. When tightening the loop, you work it into the hole with your fingers until it is time to squash it flat.
I have taken several pictures from different angles in order to give you an idea of the loop the strip must have in order to form the right type of point.
Note that there is a slight risk that you now sit with a half-finished star that is a mirror image of what is shown in the pictures. You should be able to figure out if this is the case by studying the pictures closely. I have tried to have focus in places where it counts.
Step 8: Adding Flat Point (with Folding)
This time I will show you the safe, but slow way of doing it. Pre-folding the point before pulling the strip through the star.
Step 9: Four Flat Points Done
It is now time to turn the star over and demonstrate a third way of making the flat points.
(First picture shows the top, the second shows the old flip side, the new top.)
Step 10: Adding Flat Points (third, Mixed, Method)
We quickly form a loop and tuck the strip, as in the first method. Then, one of our fingers press a fold in the "root" end of the star, the end that isn't "sucked" into the star as we pull the free end.
As the to-be-point runs out of paper, we must push on it a bit to obtain a good result.
The last picture what the star should look like when all the flat points have been added.
Step 11: Preparation for the Three-dimensional Points
This is perhaps the step that is most likely to be forgotten, a simple mistake that will make it very hard to recall how the 3D points were formed.
Step 12: Loop-the-loop
(Now that is a rather short strip end. I used strips with a length-to-width ratio of almost exactly 30:1. It makes the different actions fit nicely in my close-ups, but apart from that it is mostly a pain to work with too short strips.)
Step 13: The Critical Twist
For stars that have the same handedness as the one showed in the pictures, The tip of the strip should now be rotated three quarters of a turn counter clockwise. The axis of rotation is orthogonal to the base knot plane.
Or, inspired by the loop-the-loop terminology, after the stunt aircraft has made its loop-the-loop, it should stop dead, turn into a helicopter, then turn 270 degrees to the left.
Hopefully, the many pictures taken from different angles will help you stay on track.
Step 14: Carefully Tightening the Final Loop
Step 15: Turn Over and Add the Final Four Points
Step 16: Trimming Off Excess Paper
If you leave one, you can write somebody's name there and use the stars as dinner table seating organisers.