Cereal box - Dry box - Spool and Desiccant Holder (https://makerworld.com/en/models/99533-cereal-box-dry-box-spool-and-dessiccant-holder#profileId-1911855)
Plastic_Drybox_01.jpg
I printed these to realize a better storage solution for my in-use filament spools.
Plastic_Drybox_02.jpg
Each tray has a desiccant box in the back, and a hydrometer holder in the front. You can use either the standard rectangular ones, or the round ones. In the first photo, you can see both holders are printed, though you don't need both.
Plastic_Drybox_03.jpg
Here is a close-up of the rectangular hydrometer that I am using. They tell the relative humidity and temperature.
Plastic_Drybox_04.jpg
Once installed in these cereal boxes, you can now store your filament, keep it dry and see the amount of moisture in the box.
RESERVED
RESERVED
Several years ago, I saw where someone had their filament stored in plastic boxes, similar to this. They had drilled/cut small-ish (maybe an inch diameter) holes in the side of the boxes for the filament to exit, and then had stuffed sponge pieces into the holes where the filament went through the sponges. This had the double result that the sponge kept the filament inside the boxes dryer, and also smoothed the filament of any bumps to make it fit into the hot end.
Something else: I noticed that, in addition to the Amazon-linked products, the Italian Amazon site had the cereal boxes, and the hydrometers "unavailable." So I did a bit of searching...
Cereal boxes (sorted by price) (https://www.amazon.com/s?k=GoMaihe+4L+Food+Containers+for+Cereals&s=price-asc-rank&ds=v1%3AngA7dhvh9kDZQfpa52JEMHUCPIzDDpVCBlERbJG%2BWXI)
Hydrometers (sorted by price) (https://www.amazon.com/s?k=Vaikby+Digital+Indoor+Hygrometer+Thermometer)