I am getting ready to build my own robbing screens. I have found several designs on the internet some with the bottom completely open along the hive entrance and a small opening at the top, Some open completely allong the hive entrance and the top of the screen and others with small entrances on both the top and at the hive entrance. My question being which of these have you guys used found to be most effective. I have one weak hive who is getting hit hard. I put a makeshift up screen for now. I feel if I'm going the effort to make quality screens which will last for several years I want to build the style which is most effective. Any help you can provide would be great. Thanks in advance.