Of course, although the ancients could not compare fingerprints with high technology as we do now. But they still have a way. At that time, they mainly relied on human eyes to identify. Although the accuracy of this comparison result is not very high, it can basically meet the daily recognition accuracy. Now we open our hands and look at the fingerprints on our fingers with the naked eye. The difference between fingerprints is also easy to distinguish. Therefore, as far as the difficulty of naked eye fingerprint identification is concerned, this is not a sophisticated technology. In ancient times, there were many trained professionals specializing in fingerprint identification.
In addition to comparing fingerprints with the naked eye, we should know that fingerprints and signatures often exist at the same time. Not only fingerprints need to be compared, but signature comparison is also an extremely important procedure. In ancient times, few people could receive cultural education. In this case, the illiteracy rate is very high. Even many people can't write their own names, so it's not realistic to sign on paper. But there are countermeasures for everything. If they can't write their own names, they will be asked to make certain marks on the paper to confirm that they really know the words on the paper. It can be seen that writing on paper is an important method to replace not signing.
Existence is right, what's more, it has existed for thousands of years, and it has its advantages and scientific nature that paper painting can always be widely used by people.