Because seal 36 is sufficiently protected from the external environment and would only be exposed to the electrochromic medium 38 and an inert gas between substrates 12 and 14, first seal 36 may be made of a material that need not be cured, such as a butyl rubber, silicone, EPDM, polyisobutylene, Teflon, neoprene, viton, or the like.