What’s the Difference Between Curly Koa and Select Koa?

The difference between curly koa and select koa comes down primarily to the figure—the visual pattern created by the grain of the wood—and, ultimately, rarity.

Both are genuine Hawaiian koa. Both come from the same species of tree, Acacia koa, which grows naturally only in Hawaiʻi. Both can display the extraordinary golden, amber, reddish-brown, and chocolate hues that have made koa one of the world’s most admired premium hardwoods.

But curly koa possesses something extra.

In exceptional curly koa, the grain develops a distinctive rippling pattern running across the normal direction of the grain. Under changing light, these ripples can appear to move, shimmer, brighten, darken, disappear, and reappear as the viewer changes position.

This phenomenon is closely related visually to chatoyance, an optical quality prized in certain gemstones. Just as a chatoyant gemstone can display a luminous band that seems to move as the stone is turned in the light, highly figured curly koa can appear almost three-dimensional as light travels across its grain.

Select koa can still be exceptionally beautiful. It may possess magnificent color, attractive grain, and considerable character. But it generally lacks the intense, repetitive, shimmering curl that distinguishes the rarest curly koa.

That rarity has enormous consequences for value.

Only a relatively small percentage of koa develops significant curl, and an even smaller amount possesses the combination of strong curl, desirable color, size, consistency, and structural quality needed for exceptional furniture.

This is why the finest curly koa is so highly prized—and why it can command a substantially higher price than select koa.

What Makes Hawaiian Koa So Special?

Before comparing curly koa and select koa, it helps to understand why koa itself is so extraordinary.

Koa is endemic to Hawaiʻi. Genuine Hawaiian koa is not simply a variety of acacia imported from somewhere else. Acacia koa evolved in the Hawaiian Islands and is inseparably connected to Hawaiian history, culture, craftsmanship, and landscape.

Native Hawaiians used koa for some of the most important objects in traditional life, including waʻa, or canoes, as well as paddles, surfboards, bowls, weapons, tools, and other functional and ceremonial objects.  Koa eventually became highly prized for cabinetry and fine furniture as well.

Part of koa’s attraction is its remarkable range of natural color. One board may display golden and honey tones, another rich amber and reddish brown, and another deep brown approaching chocolate.  But color is only part of koa’s appeal.

Its grain can range from relatively straight and quiet to wildly figured, wavy, and dramatically curly. That extraordinary variation means no two pieces of koa are precisely alike. That leads directly to one of the most important distinctions a buyer of fine koa should understand:  Select koa and curly koa are not the same thing.

1. Curly Koa and Select Koa Come From the Same Species

The first misconception to clear up is that curly koa comes from a special species of koa tree.  It does not.  Curly koa and select koa are both Acacia koa.  The difference is primarily in the figure of the wood.

Select koa may have beautiful color and attractive grain, but the grain is generally less dramatically figured.

Curly koa contains a rippling, undulating figure running across the normal grain. In the finest examples, these ripples occur repeatedly across the board and produce the extraordinary visual movement collectors associate with premium curly koa.

So, when comparing select and curly koa, you aren’t choosing between two species.  You are comparing different levels and types of natural figure within the same extraordinary Hawaiian hardwood.

2. What Exactly Is “Curl” in Koa?

Look closely at a beautiful piece of curly koa and you may see a series of bands or ripples running across the grain.  These aren’t painted on.  They aren’t stains. They aren't water marks. They aren’t created by the furniture maker.

They are part of the natural structure of the wood itself.  The fibers within figured wood do not all run in a perfectly uniform direction. Variations in fiber orientation change the way light interacts with the surface.

After skilled sanding and finishing, that internal structure can create alternating areas of brightness and darkness. The effect can resemble waves, ribbons, flames, or folds of silk. The more intense and consistent that figure becomes, the more dramatic the visual effect.

Exceptional curly koa therefore has two patterns working together:  the longitudinal grain of the wood and the curl crossing it.  That interaction gives premium koa much of its extraordinary depth.

3. Curly Koa Has Chatoyance

Perhaps the best way to explain the visual magic of curly koa is through the word chatoyance.  Chatoyance is most commonly associated with gemstones. The term comes from the French expression for “cat’s eye.” In a chatoyant gemstone, reflected light can form a bright band that seems to glide across the stone as either the gemstone, the light source, or the viewer moves.

Think of a fine cat’s-eye gemstone.  Viewed from one angle, one portion may appear bright while another looks darker. Turn the stone and the bright area appears to travel across its surface.

Highly figured curly koa can create a remarkably similar visual impression.  Of course, wood and gemstones create their optical effects through different physical structures. But the comparison is extremely useful because the viewer experiences something similar:  movement created by light.

Curly koa doesn’t merely have a pattern.  The pattern appears to come alive.

4. Curly Koa Looks Different From Different Angles

This is one of the most important differences between seeing curly koa in person and seeing it in a photograph.

A photograph captures one instant from one position under one lighting condition. Curly koa is dynamic.

Imagine standing in front of a large curly koa dining table.  From one side of the room, a particular band of curl may appear dark and rich. Walk several feet to the other side and that same band can become bright and luminous, while another section that previously looked bright becomes darker.  Move again and the pattern changes again.

Morning light can reveal the wood differently than afternoon light. Overhead lighting can produce a different appearance from natural window light. This is why exceptional curly koa is sometimes described as fluttering, shimmering, or almost three-dimensional.

Nothing in the wood is physically moving. You are moving. The light is moving. And the koa appears to move with you. That is the magic of curly koa.

5. Select Koa Can Still Be Beautiful

Calling one grade “curly” should never imply that select koa is unattractive.  Far from it.

High-quality select koa can have magnificent natural coloration and beautiful grain. It can display golden amber, reddish brown, deep brown, and striking contrasts. Individual boards may have flowing grain patterns and considerable personality.

For many furniture designs, select koa creates an elegant, sophisticated appearance. The primary distinction is that select koa generally does not possess the intense, repetitive curl and optical movement found in highly figured curly koa.

Think of select koa as emphasizing color and grain, while the finest curly koa combines color + grain + figure + movement.  Both can be beautiful.  Curly koa simply adds another dimension.

6. Curly Koa Is Much Rarer

Rarity is one of the principal reasons curly koa is more valuable.  You cannot simply plant a koa tree and order it to produce heavily figured wood.

Curl is a natural phenomenon.  Woodworkers and scientists have long discussed the extent to which genetics, growing conditions, physical stress, branching, and other factors contribute to figure. Particularly interesting curl may occur around forks and branching areas, sometimes referred to as stress or crotch figure.

Whatever combination of factors creates it, the practical reality for a furniture maker is straightforward:  Most koa is NOT curly.

Traditionally, only around 10% of koa is considered curly, and truly exceptional furniture-grade curly koa represents an even more selective portion of that material.

Finding curl isn’t enough, either.  The wood must also have desirable color, sufficient dimensions, structural integrity, appropriate moisture content, and enough consistency to allow multiple boards to be matched for a piece of fine furniture.

That makes exceptional curly koa genuinely scarce.

7. Not All Curly Koa Is Equal

This distinction is critical.  Simply labeling something “curly koa” doesn’t tell you how good the curl is.

Curl exists on a spectrum.  Some boards may display occasional faint bands. Others have moderate curl across portions of the surface. Exceptional boards can have intense, tight, highly consistent figure extending across large areas.

Consequently, two boards technically described as curly koa can differ enormously in appearance—and value.  An experienced koa buyer looks beyond the label.

• How strong is the curl?

• How consistent is it?

• How much of the board contains figure?

• How attractive is the color?

• How does the figure interact with the grain?

• How large is the usable section?

• Can several boards be matched closely enough to create a harmonious dining table, bed, dresser, or cabinet?

This is where decades of experience with koa become invaluable.  Martin & MacArthur has been making fine koa furniture in Hawaiʻi since 1961. Its craftsmen and wood buyers have spent generations evaluating koa not merely as lumber but as the raw material for heirloom furniture.

Selecting the finest curly koa requires an educated eye.

8. Why Curly Koa Commands Such a High Price

The economics of curly koa are ultimately a lesson in supply and demand.  Demand for spectacular curly koa is extremely high. Supply is extremely low.  And the supply becomes even smaller as quality requirements increase.

A furniture maker doesn’t simply need one beautiful six-inch piece of curly koa. A large dining table, bed, dresser, sideboard, or cabinet may require substantial quantities of compatible material.

Boards must often be selected and matched so the colors, grain, and curl complement one another.  That is difficult.  As the required dimensions become larger, the difficulty increases.

Consequently, premium curly koa can command multiples of the price of select koa. Historically, exceptionally curly material has been valued at several times the price of less figured select koa.

The premium isn’t created merely by marketing.  It reflects a fundamental reality:  Nature produces far less curly koa.

9. Matching Curly Koa Requires Extraordinary Skill

Buying expensive curly koa lumber is only the beginning.  The next challenge is deciding how to use it.

A master furniture maker must determine which surfaces deserve the most dramatic boards and how adjoining pieces should relate visually to one another.  Consider a large koa dining table.  If one board is intensely dark and curly while the board beside it is much lighter with weak figure, the table can look visually disjointed.

• The goal is harmony. 

• Color should flow. 
• Grain should make visual sense.

• Curl should enhance the design rather than fight against it.

This is one reason Martin & MacArthur places so much emphasis on selecting and matching its koa. The company has been making koa furniture in Hawaiʻi for more than six decades, and its Honolulu furniture workshop brings together craftsmen who have spent years learning how to work with this highly variable material.

The finest koa furniture isn’t simply assembled. It is composed.  The wood itself becomes part of the design.

10. Curly Koa Turns Furniture Into an Ever-Changing Visual Experience

This may ultimately be the greatest distinction between select koa and exceptional curly koa.

• Select koa can make an extraordinarily beautiful piece of furniture.

• Curly koa can make furniture that continually reveals something new.

Walk past a curly koa bed in the morning and the headboard may glow in one pattern.  See it under warm evening lighting and different portions emerge.  Walk around a curly koa dining table and waves of figure can appear to follow you.

That interaction among wood, light, movement, and viewer makes curly koa unusually engaging.  It also helps explain why people who understand koa become so passionate about exceptional curl.  You don’t merely look at curly koa.

You experience it.

And because every tree—and every figured board within that tree—is unique, an exceptional piece of curly koa furniture can never be duplicated exactly.

Why Martin & MacArthur Knows the Difference

Understanding koa quality takes more than reading a grading chart. It comes from handling the wood for generations and passing down that knowledge.

Martin & MacArthur has been making fine koa furniture in Hawaiʻi since 1961. The company maintains its furniture workshop in Honolulu, where its trained craftsmen select, match, kiln-dry, cut, sand, construct, and finish koa furniture.

Over generations, that creates an institutional knowledge of koa that is difficult to reproduce.

Martin & MacArthur looks for the characteristics that distinguish exceptional koa: rich natural color, beautiful grain, strong curl, consistency, appropriate dimensions, and the ability to match different boards into a visually unified piece of furniture.  That expertise matters because “curly” is not a simple yes-or-no designation.

• There is curly koa.

• There is highly-figured curly koa.

• And then there is the truly extraordinary koa that makes an experienced woodworker stop and look twice.

Recognizing that difference is part science, part craftsmanship, and part experience.

Conclusion: Curly Koa Is Nature’s Rarest Expression of Koa

So, what’s the difference between curly koa and select koa?  Both are genuine Hawaiian koa.

• Select koa can offer magnificent natural color, beautiful grain, strength, durability, and the unmistakable character of one of Hawaiʻi’s most celebrated woods.

• Curly koa adds something much rarer: dramatic figure and optical movement.  Its rippling grain interacts with light in a way reminiscent of chatoyance in fine gemstones. As you change your viewing angle, bands of light and dark can appear to move across the surface.

That movement gives exceptional curly koa extraordinary depth.

The finest curly koa commands a significant premium price because relatively little koa develops strong curl and even less combines intense curl with desirable color, dimensions, consistency, and furniture-grade quality.

• Its price reflects rarity.

• Its appeal reflects beauty.

• Its value ultimately comes from something that cannot be mass-produced:  Nature made only so much of it.

For more than six decades, Martin & MacArthur has selected and crafted Hawaiian koa into fine furniture intended to last for generations. That experience has reinforced a simple principle:  There is beautiful koa.  And then there is extraordinary curly koa.

Once you’ve seen exceptional curly koa move in the light, the difference becomes unmistakable.

1. What is the main difference between curly koa and select koa?

Both come from the same Hawaiian koa species. The primary difference is figure. Select koa can have excellent color and attractive grain but generally has less dramatic figure. Curly koa possesses rippling grain that creates alternating light and dark bands and can appear to move as the viewing angle changes.

2. Is curly koa a different species of tree?

No. Curly koa and select koa both come from Acacia koa. “Curly” describes a prized figure within the wood rather than a separate species of koa tree.

3. What is chatoyance in curly koa?

Chatoyance describes an optical effect in which reflected light seems to move across a material as the viewing angle changes. The term is strongly associated with gemstones such as cat’s-eye stones. Highly figured curly koa can produce a comparable visual experience because its changing grain orientation reflects light differently across the surface.

4. Why does curly koa look different when you move around it?

The orientation of the wood fibers varies within the curly figure. Those fibers interact differently with incoming light. When you move—or when the light source changes—the areas reflecting the most light also change. That produces the remarkable shimmering or fluttering appearance associated with premium curly koa.

5. Is all curly koa equally valuable?

No. Curl varies tremendously in strength, consistency, coverage, color, and quality. A board with occasional faint curl is very different from a large board displaying tight, intense, consistent curl across its entire surface. Exceptional color and large usable dimensions can increase desirability further.

6. How rare is curly koa?

A commonly cited traditional estimate is that only about 10% of koa exhibits the prized curly figure. Truly exceptional furniture-grade curly koa is scarcer still because the material must satisfy additional requirements involving color, dimensions, condition, consistency, and usability.

7. Why is curly koa so much more expensive than select koa?

Scarcity is the biggest reason. Demand for highly figured koa greatly exceeds the supply of exceptional material. Martin & MacArthur has historically noted that premium curly koa can cost several times more than select koa. Large, consistently figured boards suitable for fine furniture are particularly valuable.

8. Does select koa mean low-quality koa?

Absolutely not. Fine select koa can have spectacular natural color and attractive grain and can make beautiful heirloom furniture. “Select” should not be confused with inferior. Curly koa simply possesses an additional and much rarer degree of figure and visual movement.

9. Can you see the true beauty of curly koa in a photograph?

Only partially. Photography can capture color and some of the figure, but it freezes the wood from one viewing angle. Much of curly koa’s appeal comes from watching its light and dark bands change as you move around it. Seeing exceptional curly koa in person is therefore a fundamentally different experience.

10. How should I choose between select koa and curly koa furniture?

Start with what appeals to you visually. If you appreciate koa’s rich color and natural grain and prefer a more understated appearance, select koa can be an excellent choice.

If you want the most dramatic expression of koa—with intense figure, depth, rarity, and that remarkable shimmering movement under changing light—look for highly figured curly koa.

Most importantly, don’t buy based solely on a label. Look at the actual wood. Compare the color, grain, intensity of curl, consistency, board matching, craftsmanship, and finish.

When purchasing a significant koa piece, experience matters. Martin & MacArthur has been making fine koa furniture in Hawaiʻi since 1961 and has spent more than six decades selecting and working with this extraordinary Hawaiian hardwood.

When you see truly exceptional curly koa in person, you won’t need someone to tell you why it is special.  The wood will show you.