rubber

'As modern building materials have been developed,' wrote Japanese garden specialist Douglas M. Roth in October 2003, 'we humans have been remarkably proficient at applying them in ways that go well beyond the vision of their inventors.  Such is the case with roofing membranes, which now are widely used as liners for backyard streams and ponds.   'It's understandable that landscape designers and contractors have taken to these rubber liners.  After all, they make pond and stream construction inexpensive and easy.  But from the perspective of the Japanese gardener or quality watershaper, convenience and affordability alone do not