A new analysis technique for UV/visible spectrophotometry is described. This technique is used to accurately determine the retention of several UV absorbers (UVAs) in a rubber-modified acrylic film during xenon are accelerated weathering. The effects of reflectance, light scattering, and matrix absorbance are deconvoluted from the total apparent absorbance, resulting in an absorbance spectrum due to the UVA alone. All of the UVAs studied exhibit significant losses upon xenon are exposure, which has important implications for the longterm durability of polymers that utilize these stabilizers.