Whats the best realm level for bulk iron farming?

[Resolute]

I seem to go from either Scare Iron to Bulk Cobolt - where is the sweet spot in terms of realm level?

[Mythraelis]

For me it is swamp provisioner/herbarium medium difficulty.
Lot of iron, some zinc, minimal cobolt.

[subwaybananas]

every lower swamp biomes (under 100) on the coast.

[VashSevrem]

Around 70 I seen iron being the main resource with little cobolt.

[Martin]

Best is Herb.. Gloom is pretty empty of anything really. Hunt not particularly great and Prov is too low for any decent quantity.. I'd go with Herb for iron in bulk.

[Resolute]

I've combined a few ideas together and found that Herb - Hard mode (RL - 85) is perfect, Like Martin said Gloom and Hunt really aren't that great but Herb with the higher Real Level due to Hard is a Sweet Spot for T2 Ores and Essences