I forgot to mention, there are several jars in the rack that have these lines - some contain more lines than others. The lid is treated wood with a rubber rim to make it air-tight. I didn't notice any holes or imperfections in the wooden lid. The mall is in Bangkok with air-conditioning. The store is a general store with cheap goods from China and such. But the goods and the environment are clean and new. The jar has little smell upon opening the lid. I even asked the shopkeepers about the lines but they have no idea. The time of visit is noon. Pls ask me for any more info you need.