As I started to learn about 3D printing, the gist I learned was "it's better to store the filaments in a drybox." As I rechecked these notes, they were to a good degree from an era when PLA was rather new to the market and ABS was the goTo.
Then I learned "PLA is not really hygroscopic and can be stored freely."1
Now, I know some materials are pretty hygroscopic, but not all. So, let's try to pin it down:
Which materials are hygroscopic enough to demand a drybox?
I know that it is good practice to store all filament in a somewhat dehumidified or airtight box, but there are some materials out there that become unprintable and need drying before printing if improperly stored. This question is to point out these "special storage mandatory" filaments only. If a material can't be printed without dry storage it belongs here. If it is a nice to have, it doesn't.
This is a Back It Up question: answers need to provide one of two:
- explain personal experience, marked as such.
- provide an authoritative source (scientific paper/videos, manufacturer papers, quote from an experienced maker).
1 - For some time (month?). I do store my PLA in a closed but unsealed IKEA container with all the desiccant bags I can find as it is clearly benefitial.