Qhov teeb meem tawg ntawm nyias-walled tuag qhov chaw tuaj yeem daws tau los ntawm cov hauv qab no:
1. Kho cov kev taw qhia stamping
Thaum teeb tsa cov kev taw qhia stamping, qhov tsis zoo stamping cov ces kaum tsis raug tso cai.
2. Xyuas kom tsis muaj plam
Xyuas kom meej tias cov pwm convex hu rau qhov khoob hauv qhov zoo, tiaj tus, ntau lub ntsiab lus, sib npaug hauv lub xeev, thiab cov khoom tsis txav thaum pib txheej txheem kos duab.
3. Xyuas kom tsis txhob muaj zog tom qab
Qhov tob ntawm daim duab yuav tsum tsis sib xws thiab cov khoom noj yuav tsum sib npaug.
4. Xyuas kom tsis muaj kab cuam tshuam
Lub vaj huam sib luag sab nrauv ntawm lub tsheb yuav tsum tsis txhob tso ib qho kev cuam tshuam kab cim rau ntawm qhov chaw.
