A tremendous amount of grain sown to control the quality of the items from the silk with sericulture and silk strains until harder research would have another Silk traders learn and follow up.
Sowing the seed bank to control the quality of the silk from the Sericulture and silk varieties own research. It is difficult to know other traders and learn as quickly.
Sowing the massive spending in order to control the quality of the goods you right from the start planting mulberry เลี้ยงไหม and research species?. So hard to have other silk traders learn and follow the pace.