For questions about materials in general. For filament related questions, please use print-material tag
For questions regarding materials in general such as whether a material is capable of being 3D printed, optimal 3D printing parameters (i.e. extrusion temp), mechanical properties of materials, printer construction, etc.
Please note that material is a superset of print-material, and not only confined to being printed (i.e. filament), but also construction of a printer (i.e. acrylic, wood, steel, aluminium, etc.).
For filament related questions, please use print-material.