Product MUST be installed in accordance with current TCNA Handbook Stone Methods. White Mortar Is Recommended for Natural Stone. Minor Vein Washout Is Possible in Wet Installations. Old City Textured Finish reveals the full natural range and variation of stone. Shade variations, inclusions and inherent voids that will not be filled during production, may be present in the stone. This is intended to be part of the natural aesthetic of this product and are to be expected as well as unfilled voids within the stone, piece-to-piece, and within individual pieces. Material may exhibit random spotting of mineral deposits. This is a handmade finish, and the tooling used can impart a slight irregularity of texture on the face of the stone. Use proper troweling techniques. Directional troweling and back-buttering Large Format Tiles helps ensure full coverage, mortar transfer, and bond. We recommend a stacked joint and using a leveling clip system and back buttering the tiles to achieve a level surface. Seal and utilize a grout release prior to grouting. This product should be carefully bag grouted.