fabric size of
80cm x 10cm
Your necklace will look better if it had a pattern on it
sew the hems (to neaten it up)
and sew the longer sides together
so it is like a hallow tube
insert wool batting into the the "hole"
and move it so it is in the middle of the baric
so it should look something like this...
using a black platic elastic
you tie it around the two ends so the fabric ball does not loosed
and keep repeating so it looks something like this
and then sew on ribbon on the ends
or if your you can use a longer fabric and just sew the ends together