I notice percentages on the gilding and the equipment, as well as various categories which may or may not relate to the bonuses given by the gilding.
As best I can understand, these percentages are multiplied together, like satiations are, and the product is the final chance that, as you apply the gilding, a second (or third, etc) slot appears on the item. This chance is then reported by the 'gild item (%)' option that appears when you try the merge?
Except that the chances given are a range.... so... how's all that work?