Personally I would describe it as Edging or Beading but using these search terms yields little relevant information. Am I using the wrong words? In which case please could someone enlighten me. I'll be skinning my roof with Aluminium sheet and leaving the sides in varnished Ply so need something to "finish" the edges with.
Much like this one:

The "almost" complete teardrop trailer by AmyH12, on Flickr
Your help would be greatly appreciated.
Thanks,
Dan