How should I care for the lacquer saya on a displayed ninjato?
Updated Mar 2026
Lacquer saya are more durable than they appear but are sensitive to two specific conditions: prolonged direct UV exposure, which yellows or fades the finish over time, and rapid humidity changes, which can cause the wood core to expand or contract and crack the lacquer surface. For display, position the ninjato away from south-facing windows or use UV-filtering glass in your display case. Wipe the saya exterior with a dry soft cloth monthly to remove dust; never use solvent-based cleaners on lacquer. For the blade inside, apply a thin coat of choji oil or mineral oil to the surface every three to four months to prevent oxidation - insert and remove the blade gently to avoid scratching the interior of the saya. Storing the sheathed ninjato horizontally on a stand distributes weight evenly and reduces stress on the koiguchi (saya mouth) over the long term.