6 Eco-Friendly Wall Finishes and Why Designers Love Them

If you want to transform a white box of a room into a space with depth and character, nothing does the trick better than a specialty wall treatment. Time and again, the pros turn to eco-friendly options that contain natural ingredients like lime, ground marble, and even milk protein as a way to avoid “a literal wall of flat color,” says interior designer Peter Dunham.

Some finishes, like chalk-finish paint and limewash, are applied like regular paint; others, such as milk paint and tadelakt, come as powders you first mix with water. Still others, like Venetian plaster and Roman clay, begin as thicker putties you layer onto a wall with a trowel.

The application processes vary from quick, one-step coatings to multistep jobs that require extra work—including priming and sealing. We’ve listed them in order from the easiest to apply to the most labor-intensive.

1. Chalk-Finish Paint

Made from calcium carbonate, pigments, and water, chalk-finish paint is a nontoxic, water-based formula that’s low in VOCs (the smelly chemicals found in a lot of paint). As the name suggests, it dries with a soft matte, chalky finish. The formula comes premixed and can be applied with a brush or a roller. It’s known for having a thick consistency that easily covers wood, metal, plastic, and glass, usually with little or no prep (but do prime unfinished wood). Chalk Paint creator Annie Sloan used it on every surface in a sunroom, above.

Chalk finish paint yields a smooth, even surface that blurs textures well, so you end up with something that can hide the grain of woods like oak for a modern look. You can leave the finish as is, though uncoated surfaces will be susceptible to getting distressed (which can be beautiful) or stained (which is not). Consider a special paint-on wax that seals the surface, deepens the color slightly, and makes your walls wipeable. They will be matte but can be buffed for a subtle sheen.

2. Limewash

This weathered finish is made from crushed burned limestone, natural pigments, and water and is zero-VOC. Due to the way light bounces off crystals that form when it cures, limewash seems to change color depending on the light.

Limewash is a favorite among interior designers who want the look of plaster in a medium that’s easier to apply—it’s brushed on using quick cross strokes, as if you’re painting overlapping Xs. It shows where you stop and start, creating a mottled effect, so aim to do the whole wall in one shot. “It brings movement and visual interest without being noisy,” says interior designer Sarah Sherman Samuel, who enveloped a bedroom with Color Atelier's limewash, above.

You can apply limewash directly over surfaces like brick and stucco. On nonporous, painted surfaces or new drywall, apply a special lime prep coat. In high-traffic areas, a sealer is recommended. Portola Paints and JH Wall also offer a range of great limewash options.

3. Milk Paint

This zero-VOC, nearly matte finish contains casein (a protein derived from cow’s milk), calcium carbonate (lime), pigments, and other natural ingredients. It has a subtle, velvety sheen that some like for its antique feel, especially as it may crack and chip if you don’t apply a top coat, allowing you to achieve a distressed look.

Milk paint comes as a powder that you mix with water, and you can blend pigments to create your own colors, as designer Peter Dunham does (note the richness of the blue wall in a bedroom he designed, above). Prepare it thinner to use as a wash on textured surfaces for a mottled application or thicker for more even coverage. (Always use a mask when mixing powdered formulas.)

On porous surfaces like unpainted wood, concrete, and brick, milk paint doesn’t require sanding (unless you want a very smooth finish) or priming. If you’re painting over an already painted or sealed surface, consider a bonding agent. Apply with a soft brush for a smoother look or a stiffer, natural-bristle brush for a more rustic look—you can even use a paint roller or sprayer to cover larger surfaces. The Old Fashioned Milk Paint Company has a wide range of colors to choose from.

4. Venetian Plaster

Also called lime plaster, this ancient, naturally low-VOC finish consists of a putty made from limestone and/or marble dust mixed with calcium carbonate, pigments, and water. Although it’s been around since Greek and Roman times, it is well-suited to modern interiors because of its durable, architectural finish that can even help absorb sound. That combination of timelessness and durability led designer Jaqui Seerman to use it on the walls of a girl's nursery, above.

Venetian plaster is applied in multiple thin layers with a trowel to achieve a marble-like surface. You can vary the sheen depending on the tools you use: A plastic trowel will create a less shiny finish, and a metal one will deliver a more reflective finish. It does require a primer for proper adhesion. For extra luster, you can apply a top coat of wax with a soft cloth or a sealer with a brush. Both protect the plaster from dirt and stains, leaving the finish water-resistant and wipeable. Vasari and Master of Plaster both carry a range of colors plus offer custom options—meaning you may be able to match your favorite paint color.

5. Roman Clay

This ultralow-VOC paste is made from a gypsum plaster base that dries with a mottled finish and a stonelike texture that has a soft, tactile feel. Roman clay is similar to Venetian plaster but with a more organic quality. “It immediately creates warmth, texture, and coziness within a space,” says designer Leanne Ford, who used Portola Paints' Roman clay to add dimension to the drywall in a modern kitchen, above.

It is applied in layers with a putty knife or stainless-steel joint knife in sweeping motions so you can vary the surface if desired—smoother for more modern settings or textured stuccolike finishes in more traditional ones. (For lighter colors, it’s a good idea to use plastic joint knives rather than metal ones, which can sometimes leave gray marks on the surface.)

You can leave the final coat as is for a very slight sheen or finish with a special top coat for additional shine. (It is also recommended to seal it if using in a high-traffic area.) The walls should generally be prepared with a stain-blocking primer, although Roman clay can be applied directly over flat matte paint if it’s in good condition and not in a contrasting color.

6. Tadelakt

This finish, pronounced tad-eh-lact, was developed in Morocco centuries ago and is traditionally used by mixing lime plaster, applying to the wall, then rubbing olive oil soap into the surface to make it waterproof. (It is still used to cover the walls of hammams, or bathhouses.) Today it comes as a powder you mix with water and apply with a trowel. (Wear a mask when mixing.)

Given its waterproof nature, tadelakt is an evocative, stunning alternative to tile on shower walls and floors or tub surrounds, and it’s naturally resistant to mold and mildew. Urbanology Designs used tadelakt from Color Atelier to evoke a serene retreat in a walk-in shower, above. Made from lime, marble, clay, and other natural materials, it’s also low-VOC.

The finish is similar to other plasters but glossier and with less visual movement. You can achieve rounded corners and curves between walls and the floor for a unified surface free from seams.

Tadelakt needs to be sealed with a special wax or soap, and prep and application can be complicated, so you might want to consult a pro. Of the options here, it’s the most expensive, but you’d likely use it in place of tile rather than paint.