Hi Peter,

I am not familiar with the the Newport laser. I wonder why it wants an STL. Does it want to cut away the material defined by the STL? Or is the STL describing the material that remains?

Generally, STL files define a solid as a surface which is approximated by triangles. So I would expect to need to define the lines as volumes.If the volumes. Perhaps like this:

In[1]:= SetDirectory[NotebookDirectory[]]

Out[1]= "C:\\Users\\David\\Documents\\Mathematica Files"

In[2]:= line = Cuboid[{{0, 0, 0}, {1, .1, .1}}] // Graphics3D;

In[3]:= Export["line.stl", line]

Out[3]= "line.stl"

In[4]:= Import["line.stl"]