rubbing urushi part against urushi will cause scratches.
never forcefully rub urushi against urushi
in worst case top urushi layer could get destroyed
when using wooden urushi penrest, never rub pen against the urushi penrest.
only gently & lightly put the pen on the penrest.
use the wooden urushi penrest mainly for display purpose
for heavy / frequent use, use the 3 slotted penrest
the 3 slotted penrest is constructed from softer material than urushi, so it usually won't scratch urushi.