Symmetry

[David Thorpe]

...The center pleat will be your box pleat, and you won't want a seam running down the middle of the outside of the pleat. You'll want the seam hidden inside a pleat, which means it will actually be a bit off-center.

Thanks for the input, Matt. The way I envision it is that the center seam would be hidden in the middle of the two knife pleats opening toward each other at the center back, forming a single de facto box pleat. If the seam was on the surface, there would be either two side-by-side box pleats or the knife pleats would all open toward the outside.

I'll post pics as this thing develops. I'll likely try it on some inexpensive PV the first time.