Chu Chen gave everyone present an overview of his speculation.
While everyone suddenly understood, they also found it strange that Chu Chen knew so much about methods of forgery. If they had not known that Chu Chen was a renowned expert—and that, judging from his clothes, he did not seem short of money—they might have thought he was a forger of ancient ceramics.
If Chu Chen had known what they were thinking, he would have been thoroughly amused. Who could blame him when he had a teacher with such well-informed connections? What was more, his teacher had always insisted that he memorize these methods of imitating ancient ceramics. Fortunately, he had a photographic memory; otherwise, memorizing all that information alone would have given him a headache.
At that moment, Brother Zhang thought of something and asked, "Teacher Chu, was the black liquid around the crack just now asphalt solution?"
Chu Chen said, "Yes. That jar should have been artificially aged with asphalt."
Using asphalt solution to create an aged appearance was a common method of imitating ancient ceramics. First, asphalt was dissolved in gasoline. The asphalt solution was then applied to the surface of the object. After the gasoline evaporated, cleaning agents such as scouring powder were used to remove the excess asphalt. This created the appearance of an old heirloom.
However, the "aged appearance" produced with asphalt solution was generally uniform in color and lacked depth. Sometimes, it even showed brush marks. As long as a cotton swab dipped in No. 120 solvent gasoline was rubbed over the stain, if the stain dissolved immediately, it had been made with asphalt solution.
Chu Chen guessed that the asphalt solution around the jar's crack might have been there because the forger had poured the solution into the vessel and swished it