Acrylic paint is a miraculous substance that, unlike oil paint, can be fairly easily separated from the support on which it dried. Margi Weir uses this quality in her abstract constructions, hanging or pinning independent bits of acrylic paint on to an already painted canvas. This results in the astonishing three-dimensional paintings on display at an exhibit opening this Friday, Aug. 20, with a reception from 5 to 7 p.m. at the Inpost Artspace (located inside the Outpost at 210 Yale SE). The show runs through Oct. 8. 268-0044.