|Inputs (8,348,800)||Outputs (8,348,400)|
10,800 × Clay (8,175,600)
400 × Astral rune (173,200)
10,800 × Soft clay (8,348,400)
One can cast Humidify on an inventory of clay to turn them into soft clay. Use astral runes and equip a steam battlestaff to maximise profit and efficiency. Set up one of your "Quick Presets" to Withdraw 27 clay and an astral rune, cast the Humidify spell, which will cause the whole inventory to turn into soft clay, open the bank, Click the Quick Preset and repeat. When playing at maximum efficiency, up to 400 spells can be cast per hour, for 10,800 clay.
With the new Bank Improvement updates this can be done even faster resulting in more money and experience/hr. By setting the runes and raw clay as a quick preset, all you have to do is click the bank, click the preset, and click the humidify spell. This significantly lowers the click amount for this method.
The method above can be accelerated even further by binding Humidify to the same key as the quick preset. Click on the banker, press '1' (or 2, if that's what you chose), then '1' again.
Alternatively, casting Humidify vials may be more profitable at 883,740 gp an hour.