The lines of an outfit may make you look taller, shorter, wider or thinner. The lines of a room do the same exact thing to transform your space into a thing of beauty through decorations, window treatments and your architecture.
Vertical lines have a stately presence that draws the eye from the floor to the ceiling. They can make a room seem formal with a sense of grandeur. Vertical lines make a room seem taller and make wide spaces seem narrower. To achieve this effect with window treatments you can place long sleek drapes on the outside edges of a picture window.