Plastics — even venerable, historically eloquent plastics — hardly draw the eye. As this show’s insightful accompanying publication (a snip at £3) would have it, ‘Plastics have no intrinsic form or texture, thus they are not materials that can be true to themselves.’ They exist within inverted commas. They can be shell-like, horn-like, stony, metallic — they do not really exist on their own behalf.