Soap is like a sentient being: it ages, shrinks, loses moisture and improves with time. All measurements and weights are thus approximate. Not to worry, they are still quite accurate.
The visual patterning in some soaps (such as Contracorriente) varies considerably from bar to bar. In other soaps (The Activated Joe), it is more or less uniform. Either way, you can count on the contents being the same.
Give Soaps like wetness only when in delightful interaction with your body. In all other circumstances, they like total dryness.
Give Soaps can be used as shaving soaps and shampoo soaps. For shaving soap a beer soap with a thick lather is lovely, such as Chelita. For shampoo soaps, a bar with no exfoliant is best, such as Lunando or The Far Indias.