By day, guild members make candles (mostly of tallow) at the House of Light, and repair lamps. By night, they run about the city with glow pots, tongs, and reach-poles, lighting lamps for the city and for private individuals, usually nobles. Guild members also sell candles, and, for a fee, will guide the way through the city by night.
The guild makes its headquarters at a constantly-bright row house, complete with a huge four-foot candle out front that is lit at night. It is one of the brightest spots in the Trades Ward at night, and is easily found by the smell of lemony-scented wax.