I’ve posting in the past that I’ve been thrust into role of expert with the Vanishing Birdcage. There are definitely people who know a lot more than me, but I’ve spent some time with several different style of cages and know a little bit about what helps make the trick successful.
One thing is having a decent quality cage. You don’t need to spend thousands of dollars on a cage, but you will have to spend a few buck. What you are looking for in a cage is something that’s smooth when collapsed. Tommy Wonder in his book mentions running a loop of string around the cage to look for snags and Billy McComb in his DVDs mentions rubbing it with a silk to look for snags. Since brick and mortar magic shops are becoming less and less common, something you can look for in an online picture is how streamlined it looks. Does it have a lot of bumps when collapsed? If you think it does, look for one that has less.
The cage that I use when collapsed is very streamlined and doesn’t have much bulk. It will easily fit through my wedding ring with the bird inside the cage! While having less bulk is important, the cage having less snag points is more important!
People always ask me what kind of vanishing birdcage do I use, and unfortunately I don’t know. It was given to me when I was a teenager by a magician because it had some broken bars. Some things to consider when picking is cage is how you are going to use it and how you need it to be on your body after the vanish. Blackstone Jr used that small Abbott’s cage because he needed to wear it for half of the show up his sleeve.
The main thing you are looking for is something that won’t get caught on your sleeve. Once you figure that out, you’re good to go!