[4woodenboats]

That is NOT a paper plant, but I am am fairly certain the exhaust pipe is a muffler from an Earth Mover or other large diesel .

Paper plant exhausts look nothing like that, and they exhaust STEAM, not smoke.

I just searched the web for paper plant smoke pics, and every one labelled as such either showed white steam or was shot with the sunset in the background, which of course changes the color of the water vapors from tighty whitey to skidmark brown.

This picture was was obviously shot at either sunrise or sunset, as the light is at/slightly below the horizon, and at one side. Even the tint on this one is due to the shadow of the (probably rising) sun.

This pic is a fraud.

[TLI]

That is NOT a paper plant, but I am am fairly certain the exhaust pipe is a muffler from an Earth Mover or other large diesel . This picture was was obviously shot at either sunrise or sunset, as the light is at/slightly below the horizon, and at one side. Even the tint on this one is due to the shadow of the (probably rising) sun.

Yep.

Here is another "paper plant."

[TheThinker]

That is NOT a paper plant, but I am am fairly certain the exhaust pipe is a muffler from an Earth Mover or other large diesel.

You're right, I can see the little metal flap on top of the exhaust pipe that pops up when accelerating.