As the Boppard establishment got into financial difficulties, Thonet sold it and emigrated to Vienna with his family. There, he worked with his sons on the interior decoration of the Palais Liechtenstein[disambiguation needed] for the Carl Leistler establishment. In 1849, he again opened his own shop together with his four sons. A few years later, in 1853, he transferred the company to his sons under the name Gebrüder Thonet. In 1850 he produced his Nr 1 chair. The Great Exhibition in London 1851 saw him receive the bronze medal for his Vienna bentwood chairs. This was his international breakthrough. At the next World’s Fair, Exposition Universelle in Paris 1855, he was awarded the silver medal as he continued to improve his production methods. In 1856 he was able to open up a new factory in Koryčany, Moravia. Its extensive beech woods were of great significance to his enterprise.

In the 1830s, Thonet began trying to make furniture out of glued and bent wooden slats. His first success was the Bopparder Schichtholzstuhl (Boppard layerwood chair) in 1836. Thonet gained substantial independence by acquiring the Michelsmühle, the glue factory that made the glue for this process, in 1837. However, his attempts to patent the technology failed in Germany (1840) as well as in Great Britain, France and Russia (1841). Thonet’s essential breakthrough was his success in having light, strong wood bent into curved, graceful shapes by forming the wood in hot steam. This enabled him to design entirely novel, elegant, lightweight, durable and comfortable furniture, which appealed strongly to fashion – a complete departure from the heavy, carved designs of the past – and whose aesthetic and functional appeal remains to this day.

At the Koblenz trade fair of 1841, Thonet met Prince Klemens Wenzel von Metternich, who was enthusiastic about Thonet’s furniture and invited him to the Vienna court. In the next year, Thonet was able to present his furniture, and his chairs in particular, to the Imperial Family.