If you have a film you probably need to know its thickness. Film thickness measurements are important to everything from polymers to epitaxial 2D materials, but choosing the optimal technique is often not straightforward.  We will discuss some advantages and complications of several methods available at Penn State.  Techniques to be highlighted include:  X-ray methods, SEM, TEM, optical methods and other destructive and non-destructive techniques. Are there really 101 ways? Come find out.