When first learning to make phase boxes as a student employee at a university library in the late 1990s, I was taught Style 1, pictured above.  Then I drifted away from libraries for a few years, and when I returned, I worked in a few different labs that all made a slightly different style of phase box, Style 2, above.  Did I miss some kind of revolution in phase box construction during the early years of this millenium?  Why does this second style of phase box appear to be so prevalent now?  The design of Style 1 seems to have four clear advantages: (1) it uses less board material, and is therefore slightly more economical than Style 2; (2) the overall spine depth is one board thickness thinner than Style 2, which for massive boxing projects housed in tight shelving conditions can add up significantly; (3) the cord on the inside of the box is hidden between the inner and outer wrappers, which I find to be a more elegant construction than securing the cord on the inner face of the flap with Tyvek tape; (4) the fastening cords wrap around a sturdy outer crease of folded board rather than a cut board edge.  Both styles take the same amount of time to construct.  Are there significant advantages to Style 2 which I am overlooking?  The Parks Library lab has constructed both styles of phase box in the past, but after a quick poll and discussion about the pros and cons of each style, the conservation staff has unanimously decided to standardize phase box construction by using Style 1.