1. The glue of the high-quality film must be transparent. If the color of the front and back of the film is inconsistent, it is not a high-quality material;
2. The glue for the high-quality film must be environmentally friendly. Tear off the bottom, pinch the PVC with both hands and knead it for 1 minute. If it smells pungent, it means that the glue is not environmentally friendly;
3. Look at the uniformity of the glue. Tear off the bottom paper and check whether the glue is applied evenly under the light. If the glue is obviously unevenly applied, it means that the glue is applied by poor equipment;
4. See if the PVC color is pure. Tear off the bottom paper and stick it on the transparent or semi-transparent PVC. Observe the color of the PVC after light transmission close to the light to see if it is uniform. If you find the color after light transmission is like a "flocculent" in the ink poured into the water, the color is in shades. It means there is a problem with the quality of PVC;
5. Observe whether the PVC film shrinks significantly (above 5mm). If the bottom paper of the film is exposed more, it means that the material itself is too shrinking;
6. Observe through lettering performance. A good logo film has excellent lettering performance, which can engrave Chinese characters of about 3mm in size and English of about 2mm, and because the silicone oil on the backing paper is properly controlled, it is very easy to uncover the characters, and the glue will produce "drawing" when uncovering the characters. shape.