After we ran last week’s feature “Making Multiples: Cavity Molds for Handmade Ceramic Tiles,” we received an inquiry from a reader about making tiles for an outdoor installation. The reader wanted to know what type of clay she should use to ensure that the installation would withstand great temperature fluctuations. To address this question, we decided to go to someone with a lot of experience in this matter: DeBorah Goletz. In 1998, DeBorah was commissioned to design and install a series of ceramic tile murals for the Sheepshead Bay Road subway station in Brooklyn. For this, DeBorah needed to do much testing to be sure the murals would survive New York’s hot, humid summers and its bitter cold winters. In today’s feature, author David Kaplan shares DeBorah’s testing methods.