Filtering (漆漉し [urushi-koshi] / 濾過 [roka])

Filtering is the straining of urushi to remove dust, skin, and impurities that can cause surface defects. Clean lacquer flows more evenly, cures more consistently, and polishes to higher clarity. Filtering is also important when lacquer is pigmented, as it helps prevent clumps and streaks in colored coats.