Sealers are used to protect stone from etching and staining. You'll need to seal just after installation, and then at least once a year. But it's crucial to know which kind of sealer suits your stone. Good for stones such as granite, penetrating sealers fill the pores below the surface with a moisture-repellent compound and leave no surface residue. Topical sealers, which remain on the surface, work well with porous stones such as marble and limestone, which need surface protection from acids. Look for products from Miracle Sealants (miraclesealants.com), Stone Care International (stonecare.com), and the HMK Stone Care System (hmkstonecare.com).

The Stain Event

Even sealed stone can stain if liquids are left on the surface for too long. The remedy? A poultice. Poultices are sticky, absorbent pastes that soak into stone, rehydrating stains and sucking them out. Typically, a dry base, such as flour, sawdust, or even paper towels, is combined with a wicking fluid, like hydrogen peroxide (for coffee, tea, or mineral spirits (for paint). Although you can buy premade poultices at home centers, you can make your own by following these instructions from The National Training Center for Stone and Masonry. Trades (ntc-stone.com).

If the stain resists poulticing, you may need to consult a stone specialist. Blot the stained area with cold water and mild soap. Rinse and dry.

1. Mix flour with the wicking fluid appropriate for the type of stain you're removing; it will form a thick, peanut-butter-consistency paste.

2. Apply a 1/4-inch layer of the paste to- and at least 1/4-inch around- the stain.

3. Cover the area with plastic food wrap, taping down the edges with low-conduct tape. Allow the poultice to sit for 12 to 24 hours. Remove the plastic and keep uncovered until thoroughly dry. Carefully remove the paste with a plastic putty knife. Rinse the area. If the stain is lighter, re-poultice until gone.