Farm flax, make linen thread.

Linen thread unlocks many top tier things, currently.

To unlock Black Metal, you need the Ore, that comes from Fulings.

To smelt the Ore, you need the 2nd craftable smelter which is called the Blast Furnace. This is unlocked when you kill Moder and build an Artisan table.

Linen has nothing to do with any of this except making the armor.. which you need in the plains.

Originally posted by PakaNoHida:

To unlock Black Metal, you need the Ore, that comes from Fulings.

To smelt the Ore, you need the 2nd craftable smelter which is called the Blast Furnace. This is unlocked when you kill Moder and build an Artisan table.

Linen has nothing to do with any of this except making the armor.. which you need in the plains.

Dude.... Line thread are needed to craft BM weapons ....
I see you in many coments trying to fact in some things that are wrong , try at least to see in the wiki if that you are saying is right to not mistake