Any kind of material, any kind of craft, has a well-made product, but also has a very trashy product. To distinguish a product from a good one, despite the good use of raw materials, the work is also very critical, good workmanship, the same material feel is completely different.
1, observe the front of the protective cover
Products should be placed slightly flat, eyes flat as the product plane, this time the surface defects of many products will be at a glance, many consumers look at the product, like the positive look at the product, so that you can not observe some subtle flaws. The most common defect is the surface wave pattern. This pattern can only be seen from the side light, and there are dust points. These points will generally have, depending on the size and quantity. This sidelight method can also be used inside and outside the product.
2, observe the side of the product and feel it by hand
Many products are positively done well. The sides and interiors are very general. The side that reflects the difference is the inside and the inside. If the side and the inside are all exquisite, then the positive is even more important. The side is generally a part of the mold, the processing of the parting line directly determines the grade of the product, visually, if the burrs are uneven, it is a typical low-end product, where the fingernails are used to scrape up and down the parting line. The smaller the feeling, the better the workmanship will be. Good workmanship, stage difference should be controlled within 0.02mm.
If you look closely at the area to see the split line, it's a good product. There is also a place to observe the perimeter of the hole, and the periphery of the hole is also a hard-hit area where burrs occur. With a finger sliding along the outermost edge of the product, you can also feel the presence of burrs. A good product feels smooth, and the poor feel is rough and stinging.