According to some embodiments curtain assemblies are provided having fabric curtains with brush edges that are mated to the fabric curtain. The brush edges are configured to extend laterally from the curtain to contact, for example, the side edges of the opening in which the curtain assembly is installed and remain in contact with the side edges during movement of the curtain. The brush edges can be configured to deflect along the plane of the motion of the curtain to maintain the contact between the curtain and the side edges. In some embodiments, the curtain assemblies can include optional side tracks configured to receive the brush edges, for example, to improve the connection between the brush edges and the side edges.