In various posts I've seen it said that Europe was a backwater and offered nothing to their Asian trading partners save silver and gold until the 1800's. Is that true or is it just a popular historical myth?
That's how China's Qianlong Emperor saw it in rejecting a British request for trading posts in 1793:
... our Celestial Empire possesses all things in prolific abundance and lacks no product within its own borders. There was therefore no need to import the manufactures of outside barbarians in exchange for our own produce. But as the tea, silk and porcelain which the Celestial Empire produces, are absolute necessities to European nations and to yourselves, we have permitted, as a signal mark of favor, that foreign hongs [groups of merchants] should be established at Canton [Guangzhou], so that your wants might be supplied and your country thus participate in our beneficence.
But even if Chinese demand was lower than elsewhere, Asian purchases weren't negligible: recorded exports to all Asia by Britain alone averaged £900,000 annually in the decades before the late 18th-century surge in manufactures (BR Mitchell, Abstract of British historical statistics), upwards of a sixth of the value of European imports from the region, and Continental powers also sent some goods to trade alongside their silver shipments.
So while most purchases had to be covered in bullion (a lesser proportion in early industrialising Britain's case), exports offset part of the outlay. It was only with the rise in tea imports and general prices at the end of the century that Britain's widening regional deficit became more alarming (Continental traders having reined in their shipments after Pitt's 1784 reduction of the tea duty ruined the lucrative smuggling trade).