New York tea merchant Thomas Sullivan often sends tea samples to potential customers. In order to reduce costs, he thought of a way to put a little loose tea in several silk bags. At that time, after receiving the silk bags, some customers who had not brewed tea at that time often threw these silk bags into the boiling water because they didn't know the process of making tea. Gradually, people found that the tea packaged in this way was convenient and easy to use, and they gradually formed the habit of wrapping tea in small bags. Someone suggested to him that the silk bag was too dense, so he switched to cotton gauze and started formal commercial sales. In 1903, Sullivan applied for a patent for tea bags. By 1920, tea bags were widely used in the US restaurant industry.
