Lightstruck wines are those that have had excessive exposure to ultraviolet light, particularly in the range 325 to 450 nm.[8] Very delicate wines, such as Champagnes, are generally worst affected, with the fault causing a wet cardboard or wet wool type flavour and aroma. Red wines rarely become lightstruck because of the phenolic compounds present within the wine that protect it. Lightstrike is thought to be caused by sulfur compounds such as dimethyl sulfide.