“I can easily tell when the tiles were made by their thickness,” Mr. Rego said, illustrating his point by lifting up some azulejos to show how they became thinner over time, from around 2.5 centimeters (just under an inch) in the 16th century, 1.2 centimeters in the 17th, 1 centimeter in the 18th and even thinner today.
No commission, restoration or custom order is too small, Mr. Rego said. “We will reproduce four tiles or 4,000” at a cost of about 20 euros, or $22, per tile, he said.
The company also restores azulejos, Mr. Rego said, like those in the U.S. Embassy in Lisbon from the 1960s and ones in the Lisbon home of the French fashion designer Christian Louboutin. An artist, Sónia Guerrinha, is restoring a panel from an old palace in Sintra that is being turned into a hotel. There are portions of individual tiles missing, as well as entire sections of blank spaces where the azulejos had fallen off because, Mr. Rego said, “it’s humid in Sintra.”
That natural calamity provides Ms. Marques with the most exciting part of her job. “I have to imagine what it looked like,” she said in the restoration studio. After researching in the company’s library and studying what remains of the panel, it’s her call. “I will provide a sketch of the design,” she said, and when it is approved she will complete the many steps that turn it into a finished azulejo.
For antique tiles, recreating the background color is key, and the formula is guarded. “We have our secret recipe, like Coca-Cola,” Mr. Rego said.
Azulejos are such a part of Portugal’s identity that representations of them can be found on the sides of tuk-tuks lining Lisbon’s majestic waterfront square the Praça do Comércio and on tubes of toothpaste on pharmacy shelves. “Azulejos represent a genuinely unique expression of Portuguese culture,” Dr. Pais said. “They are not just tiles.”
