I'll politely disagree with the mold on crackled tiles. While a cracked surface can hold more water than typical ceramics with a solid glaze, a decent air flow, shower cleanliness, proper waterproofing under the tiles and a proper sealant on the tiles will go a very long way to preventing mold. We've restored historic showers using crackled glaze finish tiles with great success. Subway Ceramics supplied the tiles. You can also find double glazed tiles that look crackled but aren't

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