I have Necklace of Eminent Smithing... "Weapns and armor can be improved 20% better." How does this work?

Does the buff only apply when I am wearing this necklace or can I wear it, craft, then take it off?

Does it buff the gear I have already crafted passively when I equip it?

Does it only apply the 20% buff when I craft a new piece?

Can I go back and improve my armor slightly with it equipped and then remove it?

I cant test it myself atm

any improvements done with the necklace one are 20% better. These improvements don't go away if you take off the amulet and are not applied to stuff you already have

Only applies to workbench and grinding wheel improvements as far as I know. It wont do anything for crafting new equipment.

Oh also I think more than one piece will stack the smithing buff, plus bs pots.

The buff only applies when you are wearing the +Smithing item. You only need to wear it when you craft.

It does not buff gear you are already carrying.

It does not actually do anything when you are crafting a new piece. The +Smithing bonus is brought into effect when you take that piece to a work table (for armor) or a grindstone (for weapons).

As your +Smithing increases, you can indeed re-improve existing equipment to increase their damage or armor rating.

+Smithing allows you to improve weapons and armor to a frankly ludicrous degree and it is totally worth pursuing.

Don't neglect potions, either. The premade smithing pots from NPCs are fine, but the ones you craft yourself will eventually be vastly superior.

The ingredients with Fortify Smithing properties are: Blisterwort, Glowing Mushroom, Sabre Cat Tooth, and Spriggan Sap.