The static friction is high enough that the beads will only move if you push them, but low enough that they are easy to push. The necklace is made of 2 strands, joined at the endpoints. Put one strand on the table in the shape of y=sinx, the other goes on top of it in the shape of y=−sinx. The beads go around the crossing points of the 2 strands, as rings in the x,z plane. (You don’t have to make an exact sine wave of course, anything that yields the same topological result will work, and to loop the beads around the crossings the way I’ve described, you″l have to thread the strands through the beads before joining them at the end.) Having the crossings pass through the beads increases the friction, since the bead is redirecting some of the tension in the strands.
In theory, putting beads in the normal way on a single strand could also work, if the diameter of the strand and the hole size of the bead were well matched. (You’d want fray-proof string for threading that not to be a huge pain, though.)
The static friction is high enough that the beads will only move if you push them, but low enough that they are easy to push. The necklace is made of 2 strands, joined at the endpoints. Put one strand on the table in the shape of y=sinx, the other goes on top of it in the shape of y=−sinx. The beads go around the crossing points of the 2 strands, as rings in the x,z plane. (You don’t have to make an exact sine wave of course, anything that yields the same topological result will work, and to loop the beads around the crossings the way I’ve described, you″l have to thread the strands through the beads before joining them at the end.) Having the crossings pass through the beads increases the friction, since the bead is redirecting some of the tension in the strands.
In theory, putting beads in the normal way on a single strand could also work, if the diameter of the strand and the hole size of the bead were well matched. (You’d want fray-proof string for threading that not to be a huge pain, though.)