Apparatus and associated methods relate to semi-custom facial breathing masks having selectively removable material which when removed alters one or more facial fitting dimensions to provide a more customized or personalized fit to a wearer's face. In an illustrative embodiment, the facial breathing mask may be customized based upon facial dimensions determined using image data corresponding to a wearer's face. In some embodiments, a mask customization module may modify the shape and/or size of the facial breathing mask. For example, a processor may select, from different mask blanks, an optimal mask blank corresponding to image data corresponding to the wearer's face. The processor may determine the customization operation to perform on the selected mask blank based upon the image data and the selected mask blank. Some embodiments may provide mask customization based upon personal preferences. The system may advantageously provide an optimally fitted mask and/or personally customized mask for the wearer.