"The difference is that permeability doesn't depend on thickness and permeance does. It's the same as the difference between density and weight. Permeability is like density. Permeance is like weight. The former is an intrinsic property. The latter is extrinsic."
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.