Varnish vs. Polyurethane vs. Lacquer: The Difference Between Finishes (2024)

A finish coat adds protection and beauty to woodwork. It can make good projects shine if done right, or excellent woodworking appear shoddy if not. Consequently, it’s essential to select the proper finish for your project.

But with so many different finishes to choose from, even experienced DIYers often feel overwhelmed with options. Luckily, we’re here to help!

We asked woodworkers, painters and furniture makers about the key differences between polyurethanes, lacquers and varnishes, and what products they recommend for DIY applications.

What Is Polyurethane Wood Finish?

If you think “polyurethane” sounds like the name of a plastic, you’re absolutely right. A liquified plastic resin, polyurethane (often simply called poly) hardens after application. It’s available in a range of sheens, as well as stain/poly combos.

Poly provides a thicker layer of finish than lacquers or varnishes. As president and owner of Picazzo Painting, Anthony Lara’s 30 years of experience taught him to appreciate the durability of polyurethane.

“If you’ve got a busy household or high-traffic areas, this could be your hero,” Lara says. But if it gets damaged, he says, “repairing that thick, plastic-like layer isn’t a walk in the park.” Luckily, the initial application is forgiving, making it a popular choice for beginners.

Nick O’Keefe of Oak City Coatings says it’s important to “understand the product you are using.” Manufacturers tell him many DIYers and pros fail to follow directions — a common mistake. Inadequate prep and the wrong application methods can doom even the best intentions.

The specifics for poly:

• Best uses: High-traffic areas that might take a lot of abuse.
• Durability: High.
• Dry time: Medium (two to four hours).
• Ease of application: Easy.
• Application methods: Brush, wipe-on, spray.
• Cost: Low ($10 to $25 per quart).
• Safety and sustainability: Water-based, low-odor and easy to clean up. Oil-based has higher VOCs.

What Is Lacquer?

A clear, fast-drying finish that, unlike polyurethane and varnish, doesn’t require sanding between coats. The additives in lacquer slightly dissolve the previous layer, allowing the new coat to blend into the existing layers. This creates a single, solid protective surface.

Lara praises lacquer’s ability to “bring out the wood’s natural beauty, making those grain patterns accentuated. You’ve got options, too — you can go high-gloss or dial it down to a more mellow matte.”

Industry veteran and Newline Painting Owner Phi Dang likes lacquer’s smooth and polished look. However, he says, the thinner layers “make it more susceptible to scratches, and it may not offer the durability needed for a high-traffic area.”

Many DIYers prefer spray-on lacquers because of their easy application and quick dry time. The speedy drying also makes it practical for areas with dust or pollen in the air. (If you can keep the air clean for a half hour, you’ll likely be OK.)

• Best uses: Fine furniture and detailed woodwork.
• Durability: Durable.
• Dry time: Fast (around 30 minutes, with some dry to the touch in as little as five minutes).
• Ease of application: Spray application is easy, brush application more complicated.
• Application methods: Spray or brush
• Cost: Medium (about $20 per quart).
• Safety and sustainability: Lacquer is high in VOCs. Use a respirator with vapor-rated filters.

What Is Varnish?

Our expert panel unanimously agreed on varnish as the go-to finish for outdoor furniture. Dang singled out its UV protection, which makes it a favorite for outdoor wood furniture and decks.

Lara agreed, but stressed DIYers should know “varnishes take their time to dry.” Rushing the process, he says, can result in “peeling, cracking or even bubbles forming.”

• Best uses: Outdoor furniture, or items exposed to heat and humidity.
• Durability: High against outdoor conditions (especially spar varnish), low against high usage.
• Dry time: Long (four to 24 hours between coats).
• Ease of application: Medium. Relatively easy to apply, but requires multiple coats.
• Application methods: Brush or spray. Typically conversion varnish is sprayed, while other types are brushed on.
• Cost: High ($25 to $40 per quart).
• Safety and sustainability: Varnish generally falls between polys and lacquers in VOCs and environmental impact.

Lacquer vs. Polyurethane

There are two main differences: adhesion type and dry time.

• Adhesion: Poly finishes sit on top of the wood surface and each other. Lacquers meld with the lower layers, first by penetrating into the wood, then by melting and bonding with previous coats of lacquer. This is why poly must be sanded between coats, a step you can skip with lacquer finishes.
• Dry time:Water-based poly can take hours to dry, while oil-based poly can take up to a day. Lacquers typically dry in a half hour or less.

Both are versatile finishes. Lacquers are particularly good choices for figurines, jewelry boxes or other items that will frequently be touched. Poly works on floors, shelving and items walked on or used frequently.

Varnish vs. Polyurethane

The main difference? Varnish offers more resistance to water and sunlight. It’s also more flexible, expanding and contracting with changes in temperature. These characteristics make varnish a common choice for outdoor furniture.

“Varnish is the outdoor protector, and polyurethane is the heavy-duty defender,” Lara says.

For applications with intense outdoor exposure, look for ‘spar’ varnishes or urethanes. Spar is a boat-building term; spar finishes are often used in nautical settings due to their high resistance to water, sun and temperature. The trade-off: They’re less resistant to scuffs and scratches, since there’s an expectation nautical wood will be refinished regularly.