Some beekeepers find cover cloths are useful to lay across a box of combs to prevent the bees from running over the tops of the frames when the hive is open. They can be made from pieces of light deck-chair canvas or similar material, with a batten fixed at each end. The width of the material should be slightly greater than the length of the top-bars of the frames and the length just sufficient to allow a batten to hang over each side of the box.
The battens should be heavy enough to keep the cloth flat when laid over the hive and to prevent it being blown off by the wind. The battens, used as rollers, enable a pair of cover cloths to be used so as to expose one frame at a time when examining a set of combs in a brood box or super.