Micro x-ray fluorescence (µXRF) is an elemental analysis technique that relies on the same principles as x-ray fluorescence (XRF). The difference is that micro x-ray fluorescence has a spatial resolution with a diameter many orders of magnitude smaller than conventional XRF. While a smaller excitation spot can be achieved by restricting x-ray beam using a pinhole aperture, this method blocks much of the x-ray flux which has an adverse effect on the sensitivity of trace elemental analysis.[1] Two types of x-ray optics, polycapillary and doubly curved crystal focusing optics, are able to create small focal spots of just a few micrometers in diameter. By using x-ray optics, the irradiation of the focal spot is much more intense and allows for enhanced trace element analysis and better resolution of small features. Micro x-ray fluorescence using x-ray optics has been used in applications such as forensics, small feature evaluations, elemental mapping, multi-layered coating analysis, micro-contamination detection, and film and plating thickness.