1, the toughness of the material of the express bag itself, as long as it is made of all PE material or new material, the toughness is very strong, tensile and wear resistance! Can package the express package product safety! 2, express bag thickness, PE material and new material density is fixed, the product size is selected at the time of purchase, so you choose express bag weight, thickness, thickness generally in the thickness of 11-15 wire between the courier bags are able to fully meet the delivery requirements, the more the thickness, the cost will be the higher the weight of goods shipped, according to their own properties to choose the most suitable product express bag of their own oh! Firm 3, express bag edge, this is very important, because a lot of material in bag itself filled with impurities, edge cutting technology and lead to the bag itself, edge bonding is not strong enough, easy to crack, can not meet the safety requirements of delivery, must choose the edge technology materials are stable courier bags! 4, express bag sealing glue viscosity, not the more advanced glue will stick to Gu Yue, one-time sealing high destructive effect, need characteristics, glue can be suitable for express bag material itself of course, general glue on the more sticky point, destructive sealing effect is better! 5, the stickiness of the express bag and express face list, related to the material of express itself, the filling impurity may cause the express bag non stick surface single! To choose all PE material or new material, more stable, more guarantee! 6, in addition, the express bag needs to have the characteristics of opaque, to ensure the security of the privacy of the express package! According to the above characteristics, we choose the ordinary express bags which are relatively inexpensive and economical and affordable, and only pack some products which are relatively light weight (such as clothing). We recommend that the express bags be packed together with the sealed tape and packing together. If you don't use adhesive tape, you need to use express delivery bags with thickness thickening or new material production, so as to pack the safety of express parcels in transit.