1. Take the paper out of the packaging bag, lay it flat on the table, and wait for half an hour to see if the two sides of the paper are inclined upward or downward. If there is a serious tilt, it proves that the paper is unqualified. This is mainly because the front and back coatings of photographic paper have a great relationship with the coating quality and the temperature control in the production workshop. Once the image is seriously tilted, sometimes the printer will not feed or jam.
2. Visually inspect the surface for scratches, pricks or black spots. If the above situation appears on the surface, it proves that the photographic paper is unqualified. Because the painting workshops used by high-quality manufacturers are dust-free workshops, under normal circumstances, there will be no problems such as scratches and black spots on the painting surface, and only small factories will have the above situation.
3. Look at the smooth surface. Good photographic paper feels smooth. It has a plastic texture, while inferior photographic paper is dry. You can dip your finger in some water and touch the photographic paper coating. If it is smooth, the photographic paper coating is qualified. If it is rough or sticky, it means that the surface coating quality of photographic paper is not good and its waterproof performance will not be too good.
4. Identify whether it belongs to colloid or powder coating. In the coating of photographic paper, it is divided into colloid coating and powder coating. Colloidal coatings are far superior to powder coatings in terms of high cost, smoothness, compactness, color reproduction and waterproof performance. Identification method: photographic paper can be folded inward at the upper corner and folded several times along the crease. Then unfold the crease. Good photographic paper will not lose powder at the crease. The poor photographic paper has the phenomenon of powder dropping, which shows that low-cost powder coating is used. This coating does serious damage to the printer.
5. Look at the whiteness of this paper. There are two kinds of whiteness in the identification of paper whiteness. One is white (red) and the other is fluorescent white (blue). Studies by foreign experts show that blue light is harmful to people's eyes, and the added phosphor also has carcinogenic effect. Therefore, all domestic export photographic papers use high-grade photographic base paper and coatings. So as to present a red background and white. Inferior photographic paper is white with blue fluorescence.
6. Look at the backing paper of photographic paper. Domestic high-quality photographic paper adopts imported photographic base paper or cast-coated base paper produced by Shanghai Le Kai Company as the base paper, which has good compactness, good air permeability and water resistance and strong flexibility. The market price is around 9000 yuan/ton. Inferior photographic paper only uses low-cost white cards as the base paper of photographic base paper. This backing paper feels thick, blue and white. The flexibility is poor. Difference: You can visually inspect the back of photographic paper. If the paper is blue, it means white card; if it is red, it means cast-coated base paper. In addition, rub the photo paper with your hands a few times. If cracks appear, it means white card backing paper. If there are no obvious cracks and no powder falling, it means the base paper. White card backing paper feels hard and thick, and the coating is often very thin, so it is difficult to achieve the distinct effect of color reproduction.
7. Identify waterproof performance. Drop a little water on the surface of photographic paper, and after a few minutes, observe whether there is water oozing in front of the paper.
8. Adjust the printer to the appropriate DPI, and observe the printing effect of paper and the quick drying speed of ink.
9. Take out the whole package of photographic paper and observe whether the trimming is neat.
10, you can go to China Trademark Network to check whether the brand you are using is registered.