Paper and Humidity

What’s the relationship between those things? 

The top sides of a shopping bag we produced all burst. We gave a paper factory a call to ask the reason, and they said that this kind of thing sometimes happened when using the special paper that we ordered in the southern area in the northern region.

This was awkward. They also told us that it was closely related to humidity. South is so moist that paper never bursts, whereas it occasionally occurs in the dry northern area. 

They asked us to adjust the humidity by 8% for the next order. However, I am not sure this is right. We actually produce lots of shopping bags, but this kind of happening is our first experience. We were faced with an unexpected difficulty. 

I don’t know what to do… We should confirm the condition of paper all the time. I feel like we just scratch the surface of something….