A Black vest bag cost is very high, and the effect of environmental protection is not imagined so good. There are some retailers, will use non-toxic non environmentally friendly bags for their own to seek higher business profits. So as a buyer for single of Blank loose pack, or pay for the bags of consumers, how to distinguish blank single vest bag of true and false?   Some professionals pointed out that the environmental protection bag identification or certain professional, as non professionals can use some simple methods to identify, here, Xiaobian teach everyone a simple identification method: a reusable bag into the water, if floating on the surface of the water, then is false Blank loose pack, if sink to the bottom is really bags.