Here are a few familiar window treatment situations and recommendations for picking the right fabric:
A bank of wide, long windows that need plenty of coverage: Fabrics with some heft to them will meet your coverage needs. Make simple floor-to-ceiling panel draperies in a heavier-weight fabric, such as velvet, velveteen, corduroy, or a wool-blend fabric that limit the light. An alternative is to line your draperies with cotton duck.
A bank of wide, long windows where not much coverage is needed: A swag and cascade (made out of a nonsheer fabric with great drapability, such as a silk or blended charmeuse) that frames the top and sides of a bank of windows is a perfect treatment to provide some dress-up without much coverage. If you want to use a sheer fabric to diffuse the light, choose panels in gauze, batiste, organza, chiffon, or even lace.
A small room with drafty windows: Think about adding a drapery that covers the window entirely. Measure your drapery so that it extends well past the window’s trim molding. Then choose a heavier fabric, such as damask, in a color that matches (or closely matches) the room’s paint color. The window treatment helps block cold air. Matching the fabric with the room’s walls gives the room-enlarging illusion of unbroken wall space.
A very low-ceilinged room: Measure your draperies so they extend from the floor to the ceiling and match their color to the wall color. Be sure to install the curtain rod nearly flush with the ceiling. If you want to let in light, choose a fabric whose texture is very light yet crisp, such as voile. If you like coverage, choose a tightly woven cotton. Using a fabric that features vertical stripes is another nice way you can create a feeling of length and height in a low-ceilinged room.
A small window, the only source of light in a small kitchen: If you have a small kitchen with only a tiny window, you want to maximize the window as much as possible. Consider adding a simple valance, or if you have the ceiling height, an arched valance in the mediumweight fabric of your choice. For privacy in the evenings, you can add a simple roll-down shade, mounted out of sight under the valance for daytime.
A bathroom window that needs privacy but still needs natural light: Try a heavier voile or plissé, which both give a bit of coverage, yet let in some light. Plissé fabric comes in solids or patterns. Create a simple curtain panel with this fabric, and your problems are solved. When considering plissé, test a sample before pretreating; some plissés lose their texture when washed.