Munoz, Andre Arelius MarcusVella, AnnaHealy, Matthew J. F.Lane, David W.2019-11-292019-11-292018-08-22Munoz AAM, Vella A, Healy MJF, et al., Rapid prototyping-coded masks for x-ray backscatter imaging. Optical Engineering, Volume 57, Issue 8, August 2018, Article number 0851040091-3286https://doi.org/10.1117/1.OE.57.8.085104http://dspace.lib.cranfield.ac.uk/handle/1826/14782Coded masks (CM) often lack a self-supporting structure that is difficult to manufacture without recourse to drilled holes in place of ideal square apertures, degrading imaging properties. An alternative approach is presented with three-dimensional (3-D) printed CM molds cast with a radio-opaque material that allows square elements to be retained. Two methods are presented; hot casting a bismuth alloy (density 8.6  g cm  −  3) and cold casting with tungsten powder/epoxy resin (densities 9.6 and 10.6  g cm  −  3). A critical review of 3-D printed-CM fabrication along with some typical x-ray backscatter images is presented. A signal-to-noise ratio from both the machined tungsten and cold cast 3-D printed mask were comparable, with the former having a slight advantage. Also, 3-D printed cold cast masks were found to be more economical and easier to rapid prototype over traditional drilled tungsten masks.enAttribution-NonCommercial 4.0 Internationalcoded aperturescoded masksx-ray backscatterthree-dimensional printingArticle21309832