Humidity and Leather Covers in Korean Apartments

Central heating in winter and humid summers stress leather bindings. Portfolio books left near windows or in unventilated closets can warp boards within a season.

Winter dryness

Vegetable-tanned leather can tighten when indoor humidity drops below 35%. A loose slipcase reduces direct air flow; avoid leather conditioner unless a conservator recommends it—over-oiling attracts dust into sewing folds.

Summer humidity

Above 65% humidity, vellum and leather can swell. Do not force a swollen book flat—spine humps mean the text block is expanding. Move it to a stable room and wait before closing the clasp if you use one.

Travel

When carrying a book to a bank box, use a plain canvas wrap—not a branded portfolio sleeve that advertises contents. We supply unmarked wraps on request.

For repair of warped cases, see Rebinding & Repair.