These more traditional adhesives are formulated from solvents containing polychloroprene, polyurethane, acrylic, and natural and synthetic rubbers (elastomers). Solvent based adhesives contain significant levels of volatile organic compounds (VOCs). These adhesives are applied by brush, roller, and spray or as beads or ribbons either manually or automatically. Solvent based adhesives are available with a variety of drying and bonding times to match the application method and assembly process. These adhesives are typically intermediate in final bond strength and heat resistance providing good bond line flexibility. Because they contain organic solvent, they are less sensitive than other types of adhesives to contaminate on the surfaces to be bonded.