1, smell.
Qualified adhesive tape produced by regular manufacturers is not smelly. If you find a sour smell when buying duct tape, don't buy it. Because of the very poor maintenance of this kind of tape, especially in the low-temperature environment, the tape is easy to crack, and soon lose the glue, this tape must be a poor product.

2, look at the brightness of the film, touch the thickness of the film.
The color of the inferior double-sided tape product will be darker than the qualified tape, and if you feel it with your hand, the generally inferior tape will be relatively hard, and due to the thicker film, the actual number of meters will certainly be reduced. Good tape film are relatively soft, good tensile properties. Therefore, the brightness and thickness of the tape film is a very important two indicators, must be carefully observed.

3, look at the color of the double-sided tape.
The whiter the appearance of the transparent tape, the less impurity of the tape, to ensure normal adhesive, a hundred meters or less of tape products have a certain transparency can see the paper tube. The inferior tape is generally yellowish, and the surface is also distributed with irregular white spots. There will be impurity or adhesive dry marks with hand pressure. The process of making inferior double-sided tape must be very rough, so the color of the tape must be yellowish and there are impurities on the surface.