A Query...

[Kuruharan]

The same way European countries did it, using the sleight of hand of "privateers."
-Bethberry

I hadn't given that aspect of it much consideration. Smuggling and activities of that nature certain could account for trade between sides...as it often does in times of war.

I wonder... what about tariffs.. or was Tolkiens world full of freedom in trade.
-Eönwë

I think the more developed governments would attempt to regulate trade in some way. The regulation of trade is an ancient part of governmental function.

This ivory would have (probably) had to come from elephants (Mumakul)
-Alfirin

Ivory would definitely be a reason to trade with Harad.

I imagine the dwarves of the Blue Mountains trading with the shipbuilders of the Grey Havens for passage (at least) if not ownership of the actual ships they needed to use. After all, just because the elves built ships to the undying lands doesn't mean they didn't also build very sea-worthy ships for sale to the highest bidders for other purposes in the Middle-Earth vicinity. As much as most of them hated boats, the dwarves of the Blue Mountains had spent an age living within sight of the sea. They must surely have gotten over their water fears by then. They could (and would) have easily sailed south far enough to trade for the goods that would maximize their profit from the voyage, as any good trader would.
-radagastly

I have to agree with Legate. I don't think the dwarves ever took to the sea. While I think the dwarves probably were the primary merchants of Middle earth I think their commerce was land based.

Was it linen, woven from the flax plants that every good hobbit family grew in its garden? Clothes couldn't rightly be made from cotton, as cotton seems to raise the same difficulty as coffee climate-wise.

Could silk be harvested from local silk worms, or would it be imported? Was sheep farming a regular occupation amongst hobbits? Pity the poor hobbit who was allergic to wool.

Of what material did Arwen sew her banner?--Esty, I'm sure you can put your finger on this.

Trade need not be prompted solely by luxury items, but by any need.
-Bethberry

Now this is interesting. It reminds me of Justinian importing silk worms to start his own silk industry.

Elves seem the most likely to be the great weavers of Middle earth...but I don't think there is ever any mention of where they obtained their materials.