Postdoc Jonathan Kollmer and alum James Puckett (PhD 2012) have contributed to the Focus Issue “Imaging Methods in Granular Physics” in Review of Scientific Instruments. The open-source code (PEGS) described in the article “Photoelastcic force measurements in granular materials” is available on GitHub.
Update from January 2018: technical details and step-by-step images for particle-fabrication have now been shared by Jonathan Barés on this Wiki.