Comparisons of two urushi coated boxes, kept under the same high RH for a long time showed different behaviour. One had surface cracks, the other was still smooth and crack free. Differences in the ground structure were found. It is postulated that when grounding is done at high RH the resulting loss of water leads to a loose ground. Done at lower RHs the ground remains compact. Thus those lacquered items produced using the traditional urushi technique can be kept almost intact within a fairly wide range of humidity whereas items made by any other grounding technique should be kept under stable RH conditions. Photographs, SEM micrigraphs, diagram, table.