Muslin is so fine it is almost transparent, so weaving it with spots makes for an interesting and almost opaque fabric.
As window sheers it can be gathered or ruched onto wires, or used flat as a blind or fold over curtain to suit the required level of prettiness and privacy. It makes pretty dressing table skirts and tops and bedroom lampshades–which are especially suited to the English Country House look in combination with florals, damasks stripes and traditional furnishings.