This article describes a study of outgassing and permeation of high vacuum seal materials for use in multichamber deposition tools and other production tools to make electronic materials and devices. The study compares the performance between all metal, single use seals (copper knife edge and aluminum spring-loaded seals), elastomer O-rings, and a "compound seal." The compound seal consists of an outer baked elastomer O-ring surrounding an inner compressible aluminum seal with rough pumping (40 mTorr) on the interspace. Conceptually, this seal should perform like an elastomer because of its ability to seal repeatedly, yet should be useful in environments that are corrosive to elastomers, such as etch, chemical vapor deposition, or plasma chambers. This study focuses on measurements of quantitative gas influx, including mass-resolved measurements of permeation and outgassing, for various O-ring materials and conditioning sequences. The study compares the outgassing, leakage, and permeation of baked and unbaked elastomer seals in single ring configurations to baked and unbaked configurations of double O-rings with either an elastomer or an aluminum inner seal.