Here: the Wood Gallery Frames in a Box is a set of 15 frames in Black, Espresso, Modern White, Graywash. Find this set for purchase at Pottery Barn. Says museum curator Janet Bishop, "As a rule of thumb, hanging art on a center line of 58 to 60 inches works well. When stacking or clustering works, take into account the total height, including the space you envision between the frames, and center that. Of course, there are adjustments to be made to accommodate furniture and architectural…