The most effective way to make Tanning Fluid is by selecting a Brain and right-clicking it onto a Vessel of Potable Water. If a Bucket was used this will make 10 liters of Tanning Fluid with a 5% concentration. Tanning Fluid can also be made by boiling Birch Bark in a Clay Pot or Copper Pot although you should boil enough that the concentration is at least 5%.
Select a Vessel of Tanning Fluid and right-click it on your Tanning Tub. 10 liters of 5% concentrated Tanning Fluid is required for each Limed Hide.
Wait - as your Limed Hide begins to tan its progress bar will go up.
Each time a Limed Hide's progress bar reaches 100% it consumes 10 liters of Tanning Fluid and is converted into Leather and very rarely Fine Leather. There's a chance of your Limed Hide becoming a Foetid Ooze instead, if that happens the Tanning Fluid will not be consumed.
