Oil finishes bring out the natural beauty of wood without the glossy finish of a varnish. They provide less protection than varnishes but can be used over a stain for added protection.
Teak oil is most often a combination of oil and varnish. The oil used in teak oil is either tung oil or linseed oil, with resins or varnishes added for durability. Linseed oils are available as "pure" linseed oil or "boiled" linseed oil.
Pure linseed oil requires several days for each coat to dry. Boiled linseed oil must dry for about 24 hours. Teak oils need significantly less drying time--usually just a few hours.
Linseed oil will darken the wood more noticeably than teak oil. However, drips or runs of either oil will leave dark stains.
Linseed oils are not recommended for outdoor projects. Teak oils, which contain additives, come in a variety of blends suitable for different uses, such as indoor furniture, outdoor furniture or boats.
Teak oils are usually more expensive than linseed options because they are proprietary blends. However, they require fewer coats and less care. They also provide more levels of protection.