Final answer:
The materials tested prior to the restoration of the Sistine Chapel were paint pigments and plaster. This was necessary to restore the original appearance of Michelangelo's frescoes, which had been polluted and damaged over 500 years.
Step-by-step explanation:
Prior to the restoration of the Sistine Chapel, scientists collected samples to determine the best methods for carrying out the work. Among the materials tested were: A) Paint pigments and plaster. This was because painting frescoes, like those in the chapel, requires the use of pigment mixed with wet plaster, a technique Michelangelo utilized when creating his masterpiece. Over the centuries, Michelangelo's frescoes had to endure deterioration from factors like pollution and water damage, necessitating a delicate restoration process.
The restoration, which began in 1979 and was completed in 1994, involved cleaning soot and dirt accumulated over 500 years and repairing the plaster. Not only did they clean the frescoes, but the process also uncovered the original vibrant colors that Michelangelo used. These efforts ensured that the legacy of Michelangelo's work in the Sistine Chapel could continue to be admired for years to come.