That's the ghost mode (press F on the crafting menu) so you can put things in to see how they look but don't have to actually have the materials to do so
You can also fill it partly with materials while you grind them out :)
Oh that's actually really useful! Thanks

Decided not to make the armor as I discovered it has exact same stats as iron, which I already had.
Managed ti slay the dragon and only have 1, maybe 2 vaults left to explore. Gonna have to check out the road map for more content, amazing game but am only about 30-40 hours deep and about out of content
