In fact it WOULD BE invisible, if you are referring to geoengineering.

It would be a gas, released at MUCH higher altitudes than we see the trails at, and it wouldn't look like trails at all!

To claim that since the trails themselves block the sun from view, for some, at some times, is evidence of geoengineering, is REALLY fucking ignorant.

It's strange that so many think the trails are geoengineering, and they post links about geoengineering labs/schools/proponents/history/contents/planes yet they never actually READ about what geoengineering through SRM would even LOOK like.

They don't even read the material they use to convince us the trails are anything but contrails.

That is pathetic...and not at all surprising.