Long term storage of Onyx outside of the Dry Box will severely degrade the print quality produced by a spool. The plastic filament readily absorbs water from the atmosphere. This increased moisture content will degrade print performance, and may clog the print head.
If you need to remove the Onyx from the provided Dry Box, please store it in another air-tight container. Markforged recommends the Pelican 1430 case as the gold standard.
Only store the provided two desiccant packs with a partial spool. Any extra / leftover desiccants from previous spools of material have absorbed moisture and will permeate to the partial spool, making it wet.
Do not store partial spools of material in any type of sealable bag, as they do not protect spools from moisture. Air-tight containers used for partial spool storage must have solid walls.
If you are planning on leaving your printer or material unused for an extended period of time, just keep the spool in the Dry Box with the filament loaded in the printer. The Dry Box & desiccant do a good job protecting from moisture, and Dry Box-stored material should last up to a year before the water content is too high for printing. When re-starting a machine after a long idle period, run the Wet Plastic Purge utility until it stops steaming (which may take 2-3 runs).