Imitation gold (brass leaf) oxidizes. Without protection, it darkens within months to years depending on environment. Sealing is necessary for preservation. But the seal cannot be heavy or yellow-tinted without changing the appearance of the gold.
Traditional solutions use shellac or varnishes, but many of these yellow over time or create a plastic appearance. Modern options include acrylic spray sealers, UV-resistant varnishes, and specialized gilding sealers. The challenge is finding a seal that is invisible—that does not yellow, does not create shine variation, and does not darken the underlying leaf.
For imitation gold at NoirGold.Art, the approach is selective: use genuine gold where the work requires it, and seal imitation gold carefully only where necessary. A clear, non-yellowing polyurethane or specialized gilding seal applied very lightly is the best compromise. The seal must preserve the brightness and reflectivity of the leaf. Thickness is the enemy—thin, even application is the goal.