How exactly do I use tar and how does it behave?
To use tar:
Select tar from the pilot tools and left click to spawn a tar cloud. You could hold the left mouse button to release several, but it is hard on your engines and usually not worth it.
How it behaves:
While you are using tar your engines will take damage like Kerosene.
Tar has a cool down time so you can't spam it on the enemy.
The tar cloud will start small and grow bigger and blacker.
The bigger and blacker the cloud the more damage it does.
it takes about 4 seconds to be at full effectiveness and will dissipate after 10 seconds (actual time may vary this is just from memory)
Tar mostly damages components and not hull armor or perma hull.
Tar is team neutral and can damage your ship and your ally's ship.
Tar will block line of sight and cause you and enemy units to loose spots.
Flare gun will illuminate ships concealed by tar.
Strategies:
Tar is an area denial tool. One of its best uses is to put a tar cloud in a choke point as you are trying to escape an enemy fleet (hopefully to regroup with your ally). If the enemy ship pushes through your tar they will be easy meat if you turn arround and bite them. If they hang back and wait for it to dissipate you have created a good lead.
If you know an enemy ship will pass through the area behind you, dropping tar can cause them a lot of troubles.
Dropping tar in a dust storm with enemy ships near by can get you some lucky disables.
In a 3v3 encounter you can drop tar between elements of a spread out fleet to trigger a 2v3 or 1v3 encounter.
Tar can obscure your ship from a sniper ship to prevent component sniping as you make cover or double team its ally.