plastic or composite versions of the 80/20 or Bosch t-slot type of extrusions ?

type of extrusions ?

I once ran across a source for this but they discontinued it, saying it
wasn't very populary. The idea of extruded profiles is to build maching
framing, and the plastic is not strong enough, and it flexes. The plasic
was more for building store displays.

You might look around on the Web at various store display ("store
fixtures") outfits. One such company is where I found the plastic
extrusions.

-- Gordon

t-slot type of extrusions ?

Thanks Gordon!

My hope was to mix and match the aluminum with the plastic for the perfect combo
of strength with weight savings so I could use the
same fasters throughout a project. Probably a pipe dream - I can see over
tightening some of those fasteners to pop right through
the plastic extrusions, if indeed they exist. Anyway, off to Google I go !