Most international trade (well intercontinental anyway) was restricted almost exclusively to luxury goods. And Europe didn't have to export in that regard besides glassware up until the 19th century. Transportation costs were way too high to export/import anything that might have taken up more space across long distances (especially over land).

After the industrial revolution imports to China remained at relatively very low levels due to heavily protectionist policies by the imperial government until the opium wars.

Obviously opium was the most egregious example and by modern standards China clearly had the right to restrict its imports. Opium just happened to be the most profitable one, however importing anything else (like cotton, furs, steel tools, mechanical items) besides gold/silver was very hard as well which why (amongst other thing) many Chinese people living on the coast weren't that keen on supporting the government (of course China was in sate of near permanent civil war and endless revolts during most of the century).

So the English forced Opium onto the people of China against the will of the King of China. China rebelled, the English conquered and forced the Chinese to open their ports and accept Indian-grown opium as trade for Chinese tea.

That continued until the English found the secret plants that made the Chinese tea. They stole those plants and planted them in India.