Naming conventions for pearl strand lengths.

Pearl necklaces have unique names for how the strand 'lays' on the wearer. Many jewelry websites will call an 15 inch pearl necklace a collar or a choker, or an 18 inch pearl necklace a princess, but in keeping with our 'one size does not fit all' policy, we do not name our different lengths this way.
For comparison, we list the names of the different sizes below.

Collar:
This is the shortest length. A collar will fit snugly against the neck.

Choker:
The second shortest length. A choker will not be quite as snug as a collar, but will not drape below the collar bone.

Princess:
This is the most common or average way to wear a pearl necklace. A princess will sit just below the collar bone and will 'smile' naturally when worn. This is also usually the most complementary way to wear a necklace. Most stores will sell a 17 inch, 18 inch or 19 inch necklace as a princess, but the term refers to how the piece lays on an individual, not the length of the strand.
Using a piece of thick string or rope you can measure the exact size that fits you personally. Necklace measurements include the bail and clasp.

Matinee:
A matinee will fall a bit longer and is suitable for wearing over sweaters.

Opera:
Longer still, and will reach to, or just below the sternum.

Rope:
Think 'roaring twenties'. This denotes anything longer than an opera. Many times a rope length is purchased to be worn doubled of tripled.