Seeds of Diversity's Micro Seed Banking Primer discusses seed storage at three levels and is a go-to resource for us guiding our storage of our seeds.
Preparing for Storage
After the harvesting of the seeds, seeds will need to be stored for future use. Some seeds will be designated for planting next year (and spares for future failures), and the remaining for consumption or barter.
Seeds should be free of plant debris, dirt, rocks and weed seeds. This processes are described in Homestead Skills--Harvesting.
Seeds must be completely dry before being sealed in a container. Moisture will lead to mold, germination or damage. It has happened that the moisture from weed seeds increased the dry grain to damaging level of mositure.
Storage Containers for Seeds to Plant
Paper envelopes are the first 'packet' that comes to the mind of most people. It's what is found in retail stores. They are cheap and easily written upon. Most seem to be a 'open it one time' and no robust method to keep the remaining seeds within.
One might use small letter envelopes. They are usually the wrong size and difficult to open and reseal. A more elegant choice is to use coin envelopes. They come in a range of size. Since they are made from paper, it is very handy to write yield details and other notes. The 'flap' has to be taped shut with painter's tape. Grain weevil's can and will chew thru the paper.
We found that re-used kombucha bottles make a very secure (from bugs) way of storing seeds, as a bonus, you can see inside. Put a band of tape around the bottle to create a nice place to label.
Of course, the kombucha bottles are not always large enough. Larger amount of seeds go into organza bags, sometimes plastic and then put them into another container to keep them safe.
A salvage company had dozens of these bins that nest and stack nicely when empty, and when full, stack upon each other. They are not bug tight, nor rain tight. We use them to organize and stage seeds.
For safe storage from grain weevils, we use 5 gallon buckets with screw-on gamma lids. They also stack nicely.
Storage Containers for Usage
Containers range from half gallon canning jars, clean empty kitty litter buckets, 5 gallon buckets with Gamma Seal lids to 35 gallon plastic drums.