In general, simple curtains do not need to be lined, and sheer fabrics like handky linen and gauze should never be lined. However, lining does prolong the life of your shades or curtains by protecting them from sunlight. If your windows face west into direct sunlight, you might consider lining them. We particularly recommend lining velvet curtains as the colors are rich and more subject to fading. Custom dyed linen will also do better with a lining, especially if the color is a rich one. We use a cotton fabric made for drapery lining and treated to resist water marking.

Unlined curtains in heavier linens are opaque enough for most situations. Lining will provide more shade in a bedroom. Black out lining is available and provides more shade but does not completely black out a room unless it is used with dark velvet.