Originally Posted by LunaZ

Oh, and dimples aren't a requirement. They seemed to be in favour with news anchors and stock-brokers in the 90's and early 2000's but have gone away somewhat.
Whether or not your tie has a dimple really depends on a) how wide the tie is, b) how thick or thin the material is, and c) what style of knot and how tight you tie it.
If you wear a wide silk tie with a tight half-Windsor, then yeah, you're gonna have a dimple. A more modern slim or skinny tie, especially in a heavier fabric, will not.