Brown YY lashes are a type of lash extension that provides a soft, fluffy, and voluminous look while appearing more natural than black lashes. They are made of four strands bonded at the base into a YY shape, which gives a full effect similar to a volume fan but is applied like a classic lash, saving time and making application easier for technicians. The brown color is often a warm chocolate brown that is flattering for lighter features, and the flat base increases retention.