Guild Wars 2

I have a bunch of these Mistward items, pauldron linings, etc.

Do I need to keep these in order make the item, or just unlock them and sell them?

You can sell them once you unlock them; they’re useless after that.

Do you need to keep them until you unlock the collection?

I’ve got the Mistward Helm Lining and I didn’t see when I got it so I don’t know if it counted towards the achievement. I wasn’t planning on going for those collections yet, and need to complete all the others to even unlock the helm one.

If I need to I’ll hang onto it, but if I can get rid of it now that would be nice.

Rose said you can sell it. It unlocks upon picking it up.

As with all collections, you can sell items that are used for them once they are ticked off on the achievement panel. There is one exception that I know of that’s been added in Tangled Depths. It’s some lorebook that you can use to read lore and it also allows you to add chapters to it about different subjects. However, you can simply pick up an infinite amount of that main book by interacting with an object. Any other collectibles tend to only drop if you still need them.