Vapor permeation uses a vapor membrane feed and pervaporation uses a liquid membrane feed. It can also improve the solubility of compounds resulting in enhanced drug permeation. Gel permeation chromatography is conducted almost exclusively in chromatography columns. Narrow capillaries allow rapid permeation by mono- or bilayer water. The permeation of films and membranes can be measured with any gas or liquid. R can be interpreted as a membrane resistance to the solvent (water) permeation. As a rubber additive, mica reduces gas permeation and improves resiliency. The film increases the resistance to flow, acting as an additional barrier to permeation. ALD can be used as a permeation barrier for plastics. The lamination structure does not allow permeation of gases from outside into the pouch. Helium leaks through cracks should not be confused with gas permeation through a bulk material. This reduces the effective TMP of the system, therefore reducing permeation rate. The controlled permeation extends shelf life. Instead of allowing the permeation, blocking is also necessary. The permeation of inventive metaphors lent even his prose works the feeling of poetry.