I have already posted numerous statements on what I use to cover my greenhouses. I chose to use some really heavy solar blanket material (with a 10 year guarantee) , something that blocked UV yet allowed plenty of light to grow plants, and something that had a good and proven heat-retentive value. Simple bubble wrap would certainly be better than nothing, but would likely not last more than a season, particularly if applied on the outside of the structure. My statements are only based on personal observations.
