Includes RF shielding, "glide" (i.e., "the extent to which a full or partially full bag will slide across a marble floor"), and takes into account "bounce" (i.e., "used bills taking up more space than crisp, new dollars").
In the past year, I've been working through the problem of "bounce", the extra volume of used versus new bank notes pic.twitter.com/OhVHZU5mqu
— Jan Chipchase (@janchip) November 2, 2015