WALNUT CREEK, Calif. -- While that row of identical houses may all look the same on the outside, it's the walls inside that sets them apart.

It is the details that make our homes different, and wallcovering are a big part of that.

Wallcoverings have moved beyond just simple paint and wallpaper to become more like works of art. The options are limitless: Venetian plaster to American Clay, faux painting to color washing, murals and trompe l'oeil to foils and commercial vinyl.

Decorative wallcoverings are all the rage.

In a way, it's a concept rooted in history. Just look at European palaces from the 18th century and earlier, made famous for their tapestries and frescos.

"Nobility would hire artists to stay in the house and do nothing but decorate the home," says GiGi Miller, owner of Embellish Decorative Paint and Plaster Studio, based out of Antioch. "Today, people want that wow, too. They are starting to design their house for their interests."

Today, green living is in vogue, which is why American Clay has gained in popularity. The clay-based plaster from New Mexico is a natural, earth material that has no chemical additives. Even the pigments are natural.

Orit Yanai, who owns a studio in San Francisco, discovered American Clay in 2003. Now, she has become a leading expert in its application, and offers workshops attended by contractors.

"Faux and artistic finishes are the tricks we would use to get the look of real plaster," Yanai says. "American Clay is the real plaster. There are no more games. And I love that it has no smell or toxic dust, and it's extremely user and environmentally friendly."

American Clay can be applied to look like any plaster finish, from textured adobe to Venetian plaster.

Such versatility of looks is a mark of most wallcovering options. But one theme resonates across all of those choices: European style.

ARTE

-- WHAT IT IS: A custom ordered commercial vinyl manufactured in Italy. It mimics Venetian plaster or faux painting and adheres to the wall like a durable wall paper.

"But it's not wallpaper -- that's a dirty word," says Keith Lelliott of A Cut Above Wallcovering in Pleasanton. "It feels like leather. Usually, when people hear commercial vinyl, they think it's something ugly. But this is used in the resort hotels and is designed to look like a painted finish; it just lasts longer."

-- HOW IT WORKS: Smooth walls are a must for application, so Lelliott and his crew apply a plaster and smooth it with a wet sponge. Then they prime and paint it. Arte comes in 27-inch wide rolls (larger than wallpaper). Each strip is applied with adhesive.

-- PROS: It's durable, lasts 10-plus years and can be used on cracked walls and ceilings.

-- CONS: It's expensive, costing $60 a roll.

AMERICAN CLAY

-- WHAT IT IS: A clay-based all-natural plaster from New Mexico. Because it contains no chemicals, it doesn't cure afterwards, says Orit Yanai, who owns Orit Yanai Studios in San Francisco.

-- HOW IT WORKS: The clay powder, which comes in 50 pound bags, is mixed with water and tinted with natural dye. The type of application tool used determines the finished look, which ranges from textured to polished concrete.

-- PROS: It's an earth-based plaster that is breathable, sustainable and easy to repair.

-- CONS: It's expensive.

FAUX PAINTING

-- WHAT IT IS: A painting technique that creates a finish meant to resemble something else.

-- HOW IT WORKS: The desired finish dictates the technique and tools used. For example, color washing involves applying a solid base color on the wall, then adding a top coat of a color paint mixed with a glaze (like a sheer glue).

-- PROS: With so many possible finishes, it's very versatile and easy to change (just paint over it). It's also less expensive than plaster.

-- CONS: It lacks the texture of plaster.

MURAL & TROMPE L'OEIL

-- WHAT IT IS: Artistic hand-paintings on the wall. They can be used as accents, such as creeping ivy, or full wall pictures, such as landscapes. Trompe l'oeil is a mural that fools the eye, such as a painted window that looks realistic.

-- HOW IT WORKS: These require a tremendous amount of time and work because they are more detailed than traditional painting techniques.

-- PROS: They are unique and reflect the individual interests of the homeowner. They can make good use of alcoves and niches.

-- CONS: These are more expensive than typical paint because they take longer.