According to the query of Baidu Library, there is no shame in printing small cards. The pimples on the card surface are printed by a regular printing factory, so they are all cut directly with a knife die. Small pimples are traces left by manual paper removal. This may also happen to small cards printed by self-service, and different processes in shops are uneven. The safest way is to let the seller shoot suitable videos, such as mini-4 and polaroid concert, and there is a local laminating process for small cards. Self-printing people can only distinguish between light film and dumb film at most, and they don't know about local film covering. The cost of making a small card with special technology may be directly accepted. Moreover, the real card back is generally designed in high definition, and there will be no ambiguity. Simply put, the identification method of fake cards is:

1. Small acne is not necessarily reliable!

2. If there are some small cards with film (such as Mini 4 and Concert Polaroid), look at the front and face the light.

3. Let the seller shoot the video directly on the back of the card, which is not blurred, and there will be no grid pattern when enlarged.