This spool is suitable for aprox. 20 m filament at 1.75 mm (ca. 50g) and fits for the Maker Bot spool holders :)
Just the right size for the fun packages offered e.g. from formfutura.com
In order to avoid unspooling, I also designed a cap :)

I used a Maker Bot 2x with ABS at resolution standard setttings. Printing both parts took 45 min and used 7g of Filament.

Print out both parts and stick together. If need use Aceton to glue the parts together.