First look from the outside to see if there is any flaws, whether the tape is pasted, whether there is a hairline cut, whether it is smooth to look at the tape material(electrical insulation tape with many types, do not introduce the quality of the material evaluation, in most cases Still look at the use situation).

Look at the glue. Now that most of the glue has evolved toward environmental protection, the taste is very important. If it is very irritating, it is more likely to be a defective product(not all duct tape), and there is no anti-adhesive when it is used. After use, tear off there is no residual adhesive, if the residual adhesive on the product, this is the fatal point of the defective tape.

Note: PVC materials are basically the same, mainly to see the glue, poor quality of tape after dressing for a period of time, and then untie, you can see the glue and PVC materials separated, looks sticky, very uncomfortable, And good quality tape doesn't have that problem.