Backsplashes can be made from any tile that's somewhat water-resistant. Possible materials include ceramics, porcelain, stone, glass or stainless steel – or a mixture of any of these. Tiles that are thinner than the standard 1/4-inch-thick ceramic tiles, which are customarily used to tile walls and floors, are easier to apply because they have a lower profile. However, “bullnose” tiles -- curved and tapered edge tiles -- can be used around the edges of a backsplash to provide a smoother transition from backsplash to wall if you fall in love with a thicker tile.
The height and width of a backsplash involve both practical and design choices. Larger backsplashes provide better protection from moisture, and can tie a room together, draw attention to the sink or counter, or complement vertical or horizontal lines in the room. Consider wrapping a long run of tile around all four walls, meeting in the backsplash to add a sense of visual continuity. A vertical backsplash, extended from floor to ceiling, can add a bold, finished look as well. However, a small backsplash is perfectly acceptable, particularly when you want a subtle effect, or you don't want it to dominate the room.
Measure the area of your desired backsplash and cut a piece of butcher or kraft paper to size. Lay the paper on a flat surface and arrange the tiles on the paper to determine the placement and pattern of your tiles. Be sure and leave a 1/8- to 1/10-inch gap between the tiles to allow for grout application. Once you've arranged your tiles to your satisfaction, trace around each tile lightly using a pencil to create a map for installation.
Remove any old tile, switch plates or outlet covers from the backsplash area. Sand the area using 80-grit sandpaper to create a rough but even surface to apply mastic. Clean the sanded area with a damp rag to remove dust, dirt and old paint or mastic. Apply a thin layer of mastic across the area using a putty knife. Refer to your map for placement of the first tile, beginning either at a bottom or top corner. If you want to start in the middle, use a rule to determine the center of your area. Set the first tile into the mastic, using your map as a guide. Place the second title above or next to the first, leaving the thin gap. When you've applied all the tiles, allow them to set overnight. Fill the gaps between tiles using grout, applied with a putty knife. Wipe away any excess grout and allow it to dry completely before using the backsplash.