Craftsmanship is the quality assurance of the frame, and the craftsmanship of a pair of frames is often reflected in the details.
1. Pay more attention to the welding point of the metal frame to see if there is any crack. Due to the thermal effect during welding, the stress structure of the material is changed, or it is prone to fracture when it is stressed by virtual welding or material fatigue.
2. Whether the two temples are flat. Place the frame on the table and see if the contact point is floating. If there is a situation where one side is high and the other is low, professionals must be required to adjust the temples to achieve a left-right balance and up-down symmetry.
3. Pay attention to whether the two sides of the sill of the frame are symmetrical and whether the fixation is safe.
4. For metal frames, you can pick it up with your nails to see if there are scratches on the lacquer. For the plastic frame, carefully observe whether there are plastic particles or roughness on the surface.
5. Open and close the temples to feel the elasticity. Generally, it is wrong to think that the tighter the better, it means that the lubrication of the screw is not enough, and it is easy to cause damage to the temples. Too loose is not good, and the screw may not be tightened. Moderate tightness is the best.