Ultralight is readily?available at multiple?locations in Northern?California, including HD, Moore Newton, MacBeath and others.? Just Google it.
At least some ultralight is made from radiata pine.? The weight reduction is 30%.? I have used it for torsion boxes which get heavy fast.? Glued and screwed, it holds the rigidity just fine.? It is some dusty but manageable for occasional use.
Jim Fleming