There are several different types, even from the ones I pictured here. Just go to the nearest craft store, or yarn store, and stand around, looking befuddled. The sight of a guy in that store will be so unique, some lady is sure to take pity on you and help you find what you need.
For something like fishing line, embroidery thread bobbins might be best–smaller, made out of cardboard, but intended for thinner lengths. It would be unusual for you to find lace bobbins, which would also work, but they tend to be made of wood and be more expensive.
