THE WILDLY LONG fibers of shag rugs, in hues such as Day-Glo orange and electric blue, suited the loosey-goosey, experimental 1960s and ’70s. But the hirsute floor covering eventually flatlined, done in by its scratchy feel, reputation for harboring dirt and tendency to swallow keys and earring-backs whole—as well as its association with cocaine-fueled decadence.
Thanks to tweaks to the manufacturing formula, however, shags have resurfaced as a luxurious, denser, lower-pile and more comfortable option. In the ’70s, “shag...