The future day when there will be no more petroleum (and plastic) for hobby, we will all join you Arkon (or die), you will be our (beloved) leader...
There is plenty of plastic out there, a patch of it the size of Brazil in mid pacific, ready to be scooped, plus landfills full of it.
Also, there are plastics that can be made from grown renewables like corn.
But paper is a great way to build !