you could buy only one if you just want the color for a project or two. i know i’m not the only one doing this type of thing, but since it was new to my friends that day, i assumed it may be unknown to some others as well… so here it is!
*i’m sure any empty spool would work. i use this one because it stores easily (see below), it is almost the exact width of the bobbin, and i have a lot of them.
1) apply hot glue around the edges of the top of the empty spool (opposite that rough ridge where you secure the thread). be fairly generous 