I have a Dilemma. I am hanging 84" room darkening curtains in my bedroom that hang just a over the floor. . I want the sheer curtains behind them to let in light but am not sure if they can be shorter. Should they be the same length as the curtains or can they be shorter at 63". Are there rules regarding the hanging of curtains? Thanks for your help. sorry for the bad picture. The sheers will have to be shortened and the drapes are very dark. The drapes are burgundy and I have a long sheer on the left and a short on the right. Just can't decide which length is good.