Hi
Is it possible in V8 to convert a line weight into an outline (ie single 100mm line with a line weight of 5mm and after converting the artwork is now 100mm x 5mm rectangle)
that depends what kind of lines and what your further intentions are, if its many random lines you might have to make a macro that involves Pipe and MeshOutline or Silhouette.
if you have only single lines you can use plane Offset with option cap set to flat or round.
you can of also OffsetMultiple for many curves but that is a very bad routine for your purpose and might involve more work… so for a lot of random open or close curves you best stick to the first mentions method.
converting lines to a thickness is otherwise not possible, at least not that i would know, maybe there is a script around. you can of course also set a print width and export it as pdf.
Hi Ian -
You could try the TestCurveOutline test command. Note that this is just a test command! In a quick test here, that flips and scales the curves and can also cause bad geometry. It could serve as something to work from, though…
I’ve added this thread to feature request RH-84538 Linetype: Extract Outlines
-wim
Hi Wim
Thanks for the response. It kind of works but changes the scale, repositions and breaks the line into small segments. I’ve previously used the function in illustrator whereby I create a pattern using single lines and alter the weight of the line and then convert to outline for fabrication. would be great to have that feature in Rhino3D. cheers
you are welcome 
nice, but yeah, that is pretty unusable, still interesting that this has been given some thought, messing which such outlines is somthing i most likely would do in illustrator or affinity designer since this is representational stuff usually, but also nice to see some options.