Horn Glue

Nothing in this list is craftable in turn, so one Horn Glue is a single step: 2 units of material drawn from a single base item, plus 3 crystals.

That bill outweighs 3,130 of the 13,602 recipes tracked here and 389 of the 1,591 Alchemist ones, and 9,374 recipes nest deeper.

The single raw material does not appear in the gathering data, so the whole bill comes from vendors, drops or content this site does not track.

Horn Glue is itself consumed by 20 further recipes, spanning three of the eight crafting classes.