[Crafting 2] Boosted Cloth Apparel = Cloth Apparel + Earth Essence (+ Earth Resistance, Changes color of the Apparel)
I guess this information is not correct! I got Crafting 2 ... +1 by trait, +1 due to equip... just got an Earth Essence and couldn't combine neither with my Cloth Bracers nor with my Cloth Armour/Helmet. Could use only on my Source Hunter Sarong.
You have stumbled upon one of the formulas I believe have the highest number of exceptions. It works, but there are a lot of cloth apparels that refuse to be upgraded no matter what crafting level you have. For instance, I just tried it on the following 8 cloth apparel items with the following result:
Good Cloth Cap - Failure Old Cloth Cap - Failure Cloth Shoes - Failure Hand-crafted Boots - Failure Thin Cloth Armour - Success Homemade Robe - Success Source Hunter Sarrong - Success Terra Serrong of Education - Success
Now, this might seems to indicate that the formula does not work on cloth helmets and cloth boots, but I have seen so many exceptions and counter-exceptions that I decided to write this formulas as general as possible and then specify in the starting notes that there might be exceptions to the formulas with generic items.