Uniformity of the samples used for X-ray absorption fine-structure (EXAFS) and X-ray absorption near-edge structure studies is critical for obtaining high-quality data. Defects in the sample, including pinholes, cracks, tapers and more irregular thickness variations, generally lead to a reduced amplitude of the EXAFS oscillations and distortion of the absorption edge. These effects become worse when there is significant background absorption from other atoms in the system. In addition, if the intensity of the X-ray beam is non-uniform across the sample this non-uniformity will couple with sample non-uniformity to produce unwanted structure as a function of energy, as happens at monochromator glitches.