I was at a seminar on blacktails at cabelas yesterday. The guy seemed very knowledgeable. He uses an Elmers glue bottle wrapped in tape and filled with a fine corn starch. Much cheaper and hold more. He also does something I thought was genius... he grabs a handful of down from an old pillow and puts it in a ziplock baggie dropping one feather at a time. That way you can watch the feather and see what the wind is doing for more than 2-3 seconds and it weighs nothing.