What if? is a question that lurks at the heart of Sonya Clark’s deeply evocative exhibition, Monumental Cloth, The Flag We Should Know, opening Friday at the Fabric Workshop and Museum, 1214 Arch St., and closing at the end of the day, Aug. 4.

What if — instead of the ubiquitous and martial Confederate battle flag — America had embraced the Confederate Flag of Truce, a largely forgotten white dishtowel made for household use but commandeered nearly 154 years ago to signal the surrender of the South at Appomattox Court House?

What if this unassuming cloth with red embroidery became the symbol deployed everywhere — on mugs and stickers, on T-shirts, sweat shirts, caps, rugs, and yoga mats? What would that mean for the nation? Or as Clark put it the other day:

“What would it mean to the psychology of this nation if the truce flag replaced the flag associated with hate and white supremacy?”

For Clark, 52, who first encountered the Truce Flag at the Smithsonian’s National Museum of American History several years ago, the small piece of common cloth was almost a revelation and a window into possibilities, possibilities lost and possibilities still waiting.