It was my understanding that tax stamps were printed. They required people to purchase a liscense to sell weed, which would then allow you buy tax stamps. However at this time it was already illegal. The purpose of the tax stamps was to cfharge dealers with tax evasion as well as dealing. Many of the tax stamps are very collectible now. Tax stamps were also printed for other illegal drugs too.

That may have happened after the lthing you were talking about though.