Hermes International SCA, the French maker of Birkin bags and silk scarves, plans to build two leather factories in France in 2012 to cope with rising demand after third-quarter sales were hampered by capacity constraints. The new plants will increase capacity by 20 percent when they're fully operational in 2 1/2 years, Hermes Chief Executive Officer Patrick Thomas said today in an interview. The Paris-based company also plans to increase textile production in 2012, he said.