Placer collier is a French term that translates to "necklace length." There are various synonyms to describe the length of a necklace, including princess length, matinee length, opera length, and rope length. The princess length necklace is typically 16 to 18 inches long and is one of the most common lengths for necklaces. On the other hand, a matinee length necklace is between 20 and 24 inches, and an opera length necklace is between 28 and 34 inches long. Finally, a rope length necklace is generally around 45 inches, allowing for a variety of ways to wear it. Understanding the different lengths of necklaces can help you choose the right piece for the occasion.