Finishing Open Grain Wood Without the “Plastic” Look

Part 1: Why Finishing Open Grain Wood Demands More than a “More Coats” Strategy

When finishing open grain wood, here’s a trap even experienced finishers can fall into:

You’re working with a beautiful piece of figured walnut, open-grain mahogany, or a slab of quartersawn white oak.

You know the piece needs to stand up to daily use — spilled wine, cleaning agents, the occasional acetone-adjacent product on a kitchen countertop.

So, you do what any sensible finisher does: you build the film. Coat after coat, sanding in-between, chasing that bulletproof surface.

And then you look at the piece under a raking light.

The grain has gone flat. The wood that had depth and shadow and topography now looks laminated or “plastic.”

The finish hasn’t complemented the wood, it has buried it.

Worse, if the project lives in a production environment, you’ve added time, material cost, and dry/cure cycles for an aesthetic result that your client didn’t want.

This is the core tension in finishing open-grain species: the same film thickness that delivers chemical resistance can destroy the visual character that made the wood worth using in the first place.

Why Finishing Open Grain Wood is Uniquely Unforgiving

Close-grained species like hard maple, cherry, and birch have tight pore structures. Film builds evenly across the surface. You can stack coats without dramatically altering the way light reads the wood.

Open-grain species such as mahogany, white oak, walnut, sapele, ash, wenge, and iroko are structurally different. Their large, open pores create a natural micro-topography across the surface.

Those valleys are what give a piece of figured wood its “pop.” Light falls into the grain and bounces back at a slightly different angle than it does from the flat field surrounding it. That contrast is what your eye reads as depth.

When you fill those valleys with finish (even a good, optically clear finish), you eliminate the contrast. The surface becomes uniform. The wood looks like a photograph of itself, not the real thing.

The problem compounds with darker species. Walnut, mahogany, wenge, and similar woods have pronounced contrast between the latewood (dense, dark bands) and earlywood (the lighter, more porous tissue).

The Chemical Resistance Problem

Here’s where finishers understandably reach for more film, because chemical resistance is often directly related to barrier integrity.  A thicker, fully cured film resists spot chemicals, cleaners, and solvents better than a thin one.

That logic is sound — up to a point.

What it misses is that chemical resistance is not only a function of total film thickness. It’s a function of:

1. The resin chemistry — what the finish is actually made of
2. The degree of cure — whether the film has fully cross-linked
3. The film’s bond to the substrate — adhesion and penetration into the wood structure itself
4. Total dry film thickness — but only as one variable among several

High-quality, fully cured waterborne finishes built with chemically resistant resin systems — such as our Urethanes, Varnishes and Lacquers — can deliver excellent spot-chemical resistance at surprisingly low dry film thickness.

The performance isn’t coming from sheer mass of material. It’s coming from the quality of the cross-linked polymer network.

This is the insight that changes how you approach finishing open-grain species. You don’t need to sacrifice the grain to get a durable surface. You need to use a finish that delivers its chemical resistance through chemistry, not through volume.

What “Low-Build” Actually Means — and Doesn’t Mean

Before going further, let’s be precise about the term. “Low-build” is sometimes used as a synonym for “thin” or “diluted,” which implies weakness. That’s not what we’re talking about.

A low-build finish is one that is engineered with a high-solids content and application profile to deliver the needed performance characteristics at a lower total wet film thickness.

High solids means more of what goes on the wood stays on the wood after the water or solvent carrier flashes off.

So, you’re not spraying a diluted product and crossing your fingers. You’re applying a concentrated, engineered material in a controlled way.

The practical result: the dry film that remains after cure is thinner than what a conventional build strategy would produce, but it’s chemically equivalent or superior in terms of resistance — because the resin itself is doing the work.

For open-grain species, this approach allows you to protect the surface without filling the grain valleys.

The “valleys” remain optically and physically present. Light still falls into them. The wood still breathes visually. And the finish still does its job.

Setting Up for the Technique

Before Part 2 gets into the specifics of application — viscosity, atomization, coat count, and the sanding strategy that ties it together — it’s worth establishing what you’re optimizing for on these species.

Your target on a piece of walnut, mahogany, or open-grain oak is a surface where:

• The finish is present everywhere. No areas of bare, unprotected wood, no pinholes or holidays in the film.

• The grain valleys are still visually open. Light reads the topography of the wood. There is depth and shadow where the grain structure dictates there should be.

• The film is chemically resistant and durable. The surface stands up to the use case the piece was designed for — whether that’s a kitchen cabinet, a conference table, or a custom humidor.

• The sheen is consistent across the surface. Even on a satin or matte finish, the sheen level reads uniformly across grain and field alike.

Getting all four of those outcomes simultaneously is the art of low-build finishing on open-grain species. Part 2 breaks down exactly how to do it.

Part 2: The Technique — Viscosity, Atomization, and the Coat-Count Strategy That Keeps the Grain Open

In Part 1, we established the core problem: building film thickness to chase chemical resistance on open-grain species often produces a plastic-looking finish because there’s a uniform film sitting over, rather than in, the wood.

The solution is a high-solids, thin-film approach that delivers chemical resistance through resin chemistry rather than through raw film thickness.

Now let’s talk execution.

The technique here is proven, but it requires discipline. The temptation to “just put on one more coat” is real, and it’s where good intentions produce mediocre results.

The Foundation: Surface Prep Is Not Optional

Low-build finishing is unforgiving of substrate defects.

When you’re relying on thin, precise coats rather than film build to do the work, any scratches, mill marks, tearout, or sanding irregularities will read through the final surface.

There’s no “bury it in finish” rescue here.

For walnut, mahogany, and similar species, work through your grits systematically. On figured material, hand-sanding with the grain at the final grits (up to 400 if needed) is preferred.

A poorly balanced random orbital sander will leave hook-marks that may telegraph through a low-build finish in a way they never would under a heavy build. 

Whichever method you use, ensure your sanding procedures are well defined and your tools are running properly.

Blow out the pores with compressed air before applying any finish, because any debris in the open grain will create a rough, inconsistent base for your first coat.

For very open-pored species like white oak or coarse-grain mahogany, you have a choice to make before you start: are you leaving the grain fully open for a “natural” tactile surface, or are you doing a paste grain fill to achieve a smoother final surface while still keeping the optical depth?

Side Note: A common practice among professional finishers is to apply a wash-coat using a product like our EM1000 Universal Sanding Sealer before using a grain filler. For grain filling, our HSF5000 Primer / Surfacer / Filler is available in a Neutral Tint.

Some pros also choose to seal the wood again after filling. Since the best method depends entirely on your specific project, we’ll explore this debated topic in a future article. 

Most importantly, what you’re not doing is using your topcoats as a grain filler. That’s the strategy we’re moving away from.

Spraying: HVLP Setup for Thin-Film Application

For spraying, the single most important variable in low-build technique is atomization.

You want the finish well atomized, and the fluid volume balanced on the lean side so that it lands on the surface as a thin, uniform wet film — keep your wet film thickness at 2mil.

Viscosity: This is where finishers often go wrong. High-solids waterborne finishes generally have higher viscosity than solvent-based products at comparable solids content.

Resist the urge to thin aggressively to get the gun to spray comfortably. Overthinning a high-solids finish defeats the purpose because you’re reducing the solids-to-carrier ratio, which means more of what you spray flashes off and less stays as a film. It also increases the risk of raising the grain and extending flash times.

If the product you’re using requires reduction to spray properly through your specific equipment, reduce conservatively — typically no more than 10% with distilled water, unless the manufacturer’s technical data sheet specifies otherwise. Then adjust your setup rather than adding more water.

Gun setup: For HVLP, a 1.3 – 1.4mm fluid tip is appropriate for most waterborne topcoats at working viscosity. Turbine or compressor HVLP both work; what matters is that you’re achieving fine atomization without excessive air pressure that bounces material off the surface. A good HVLP pattern should look consistent and dry at the edges — not wet, not dusty.

By the way, there are times when you may want to experiment with the air cap size to dial-in your atomization. 

Coat weight: This is the discipline piece. On open-grain species, your target per coat is a thin, even wet film. You’re simply “tacking off the surface,” not flooding it. 

The goal is to apply enough material to wet it uniformly and allow proper flow-out without pooling into the grain valleys. In practice, this often feels like you’re not putting enough on. That feeling is correct.

Flash time: Between coats, give the material the full flash time it needs. Waterborne finishes release their water carrier as they cure, so if you apply a second coat over a first that hasn’t flashed properly, you trap moisture in the film.

On open-grain species, this is particularly problematic because the pores can retain moisture longer than the flat-field surface suggests.

When in doubt, allow more time. Then, touch the surface lightly in an inconspicuous area; it should feel dry to the touch and not tacky before the next coat goes on.

Brushing or Rolling: The Technique That Makes or Breaks Thin-Film Application

Brushing and rolling a low-build finish on open-grain species is achievable, but it requires a more deliberate technique than spraying.

The instinct to work the finish — to go back and re-stroke areas, to chase bubbles, to build material — is the enemy of both methods.

Brushing: Use a high-quality synthetic brush appropriate for waterborne finishes. Natural bristle brushes absorb water from the finish and go limp. A good quality, flagged synthetic tip gives you control over the wet film without introducing excessive air into the material.

Load and lay: Load the brush fully, then lay the finish on with long, even strokes with the grain. One stroke per pass. Do not go back.

Waterborne finishes have shorter open times than solvent-based products, and going back into material that has started to set creates drag marks and surface texture that will read through subsequent coats.

On open-grain species specifically, avoid scrubbing the brush back and forth across the grain. This pushes material into the pores and creates inconsistent film thickness across the surface — thick in the pores, thin on the field, which is precisely the opposite of what low-build technique requires.

Rolling: A short-nap roller (1/4″ or 3/16″ foam or microfiber) is a legitimate tool for flat panels and large horizontal surfaces such as cabinet doors, tabletops, and drawer fronts laid flat.

Rolling deposits a very consistent wet film thickness across the field, which is exactly what low-build technique calls for. It’s faster than brushing on wide panels and less fatiguing over a full production run.

The critical caveat for open-grain species: foam rollers can introduce micro-bubbles into the wet film, and those bubbles have a tendency to settle into and pop in the open pores before the finish levels, leaving pinholes or small craters.

To minimize this, use a high-density foam roller rather than a standard open-cell foam; keep your rolling pressure light and consistent; and always tip off with a dry brush after rolling to eliminate roller stipple, surface bubbles and get the professional look we all want. 

Overlap: Whether brushing or rolling, work in manageable sections and maintain a wet edge. The overlap between passes should be minimal; just enough to blend the edge without doubling the film thickness.

Coat weight: Same principle as spraying. Thin, even coats. You’re not filling anything. You’re building a uniform film across the entire surface.

The “Between Coats” Sanding Strategy

Sanding between coats on open-grain species with a low-build strategy is not about knocking down film build the way it would be in a conventional heavy-build approach. It’s about two specific things: adhesion preparation for the next coat, and removal of any raised grain or surface nibs.

After the sealer / first coat, once fully dry, sand lightly with 320-grit. You are not trying to flatten the surface dramatically. You are scuffing the surface for adhesion and removing any grain raise from the first water-based coat.

On open-grain species, this sanding should be “with the grain” and by hand in areas over the pores. Using a random orbital sander at this stage can easily cut through the thin film sitting over a pore edge and create a raw spot.

Between subsequent topcoats, 400-grit by hand, with the grain, is typically sufficient. Again: you are scuffing for adhesion, not building thickness by sanding down what you’ve applied.

Coat Count: Less Is More (and How to Test for the Right Build)

The question finishers ask most often about low-build technique is how many coats are needed.

The answer depends on the product, the application method, and the use case, but as a general framework:

• Spray application: 1 sealer coat + 2 topcoats is a reasonable starting point for moderate-use applications. For higher-demand surfaces (kitchen cabinets, dining tables, bar tops), 1 sealer + 3 topcoats, applied thin, builds the necessary film integrity while maintaining the open-grain aesthetic.

• Roller / Brush application: Same coat count as spray. Technique discipline matters more than the number.

Perhaps the best test for sufficient build on open-grain species isn’t visual, it’s tactile.

Run your fingertip across the surface at a low angle. You should feel the topography of the grain as slight texture and the valleys are perceptibly present. But the surface should not feel raw, absorbent, or fragile.

The finish should have a consistent, closed feel across both the field and the grain openings, even though the grain remains visually open. That’s the signature of a correctly executed low-build finish.

What to Expect Visually

When you get this technique right on walnut, mahogany, or open-grain white oak, the result is immediately recognizable. The wood looks alive. The grain has shadow and depth.

On figured material, the figure pops in a way it simply cannot under a heavy build. The sheen reads consistently across the surface because the film itself is consistent.

Remember, a high-quality, fully cured waterborne finishes built with chemically resistant resin systems — such as our Urethanes, Varnishes and Lacquers — can deliver excellent chemical resistance without high builds.

In Part 3, we’ll address the specific challenges that come up on darker, higher-contrast species such as wenge, ebony, and heavily figured mahogany, and walk through troubleshooting the most common failure modes in low-build finishing.

Until then…do you have any questions or experiences finishing open grain wood? Please share your thoughts or read what others are saying in the comments below.