Have you read the comments bellow Tony's thread? You can find many interesting questions and answers there ...
I have been using this technique now for over ten years and I have finally decided to share what I have learned. The technique is known as ‘sweating’ and is used extensively in arboretorial circles…
yamadori.co.uk
Btw, there is another way how to use black plastic bags: a technique used by Mauro Stemberger and Italian bonsai collectors. It's not a sweating technique. He collects trees (mostly a huge oaks - quercus robur) in December and then he packs them in big plastic bags and store them in unheated green house or a garage during winter. No heat, no humidity, neither mist spray is needed. I found this technique easier (less complicated) and more suitable for my taste. I've been doing some experiments with it this winter: so far so good. Here is the link:
Watch from 5:50 on if you are only interested about this technique.
