The official Micro filament
The official Micro filament is constructed to fit inside the Micro underneath the build plate. The Micro has an internal feeder for the official 1/2 lb spools, but also has a feeder for external spools. The official filament comes in spools that have 250 feet (76.2 meters) and weight about 1/2 lb (225 g) each. The filament is offered in two different materials, ABS and PLA, which come in a variety of colors.
The Micro will ship with one spool of filament. During the Kickstarter campaign backers were able to add $12 to their pledge to get an extra spool. What the actual commercial cost of the filament spools will be is still unknown, but spools can be pre-ordered for a limited time at http://themicro3d.com for $13 per 1/2 lb spool.
The Spool is installed under the build plate and is 120mm in diameter and 34mm in height.