Thomas Green & Son was a company that made special things called vellum and parchment. Vellum and parchment are very old types of paper that were used a long time ago in books and important documents, like the Constitution.
The company was started a really long time ago by a man named Thomas Green. He and his son worked together to make lots of vellum and parchment for people who needed it. They would take animal skin, like from a cow or a sheep, and turn it into vellum or parchment by soaking it in water and then scraping it until it was very smooth.
People really liked their vellum and parchment because it was very high-quality and lasted a long time. They became famous for it! Even today, some people still use vellum and parchment for very special things like wedding invitations or certificates.
So, long story short, Thomas Green & Son was a company that made really cool old paper that people loved a long time ago.