Where Shane goes in depth into the base material of our series: WOOD!

If we’re going to be nerding out about how finishes impact the look and durability of a surface, we need to first acquaint ourselves with that surface, because not all woods, even woods of the same species, are the same.

So join us on our first rabbit hole as we look into how trees make wood, and what they make it from.

We’ll get started on our first woodworking project of the series, and compare the different woods that we’re using.

Credits

Presented and Written
Shane Wiechnik

Directed and Edited
Liz Duck-Chong

Filmed at Studio Conservation, Hornsby NSW
and On Location at Sydney Botanical Gardens

Episode Special Consultant
Hiroshi Yamaguchi

Special Audio Consultants
Ben Strano
Gilly Clarke-Moon

Special Thanks
Luke Addington
Shea Alexander
Arian De Goede
Lauren Duffy
Sophie Glerum
Oliver Hull
Philip Kerrigan
Albert Kleine
Claire Martin
Nayla Maruuf
Harry T. Morris
Kathrine Sullivan
Jennifer Rome
Andy Wiechnik

Thanks to our Patreon Supporters

David Robinson
Daniel Gana
Cadge
Casey Kruse
Bob Serier
Chin
Larry
Stacey Lewis
Jacob Gillie
Jake Lunniss
Helen Taylor
Freddy Roman
John Gubbings
Joe M
Carlo
Sally
Remy
David
Karen Davis
Luis DeFana
Jacob A. Borkowski
Bruna

BASE
Luisa Casella
Peter Jorgensen

GROUND
Rho Campbell
Nick Summers
Among The Trees
William O’Neil
Sarah
Philip Norman-Ross-Burrows
Jennifer Abel
Robbie Karmel
C Castro
Thomas van kampen
Rachel Moody
benjamin Foucaud
phil
Anna Moccia-Field

FIRST COAT
Joshua Bracket

BUILD
Albert Kleine

Annotated Transcript

To download a PDF of this transcipt click here.

Let’s talk about wood.

I don’t know if you know this, but wood comes from trees. And as silly as that sounds, it’s actually really important to remember when trying to understand why wood behaves the way it does and why it looks the way it does.

Wood is not a material that was manufactured or refined or smelted like plastic, metal, or even paper. Wood is a raw material that is made by a tree to help that tree live and grow and support itself. In some ways, it has more in common with meat than metal.

Welcome to Finished, our video series on the art and science of wooden surfaces. As the series goes on, I’m really excited to look into pigments and resins and paints and plastics. Looking into optics and chemistry and the durability of woods and different techniques for applying different coatings to wooden surfaces. But I think before we get into any of that, it’s really important to understand our base material; what we’re going to be applying all these materials on top of: Wood.

And to understand wood better, we need to understand trees, and how this material is made.

TITLE: FINISHED EPISODE 1. WOOD: IT COMES FROM TREES

What Is A Tree?

There are so many different trees in the world with different qualities. For example, this is a tree [Quercus Robur]. This is a tree [Eucalyptus Saligna], this is a tree [Sequoia Sempervirens], this is a tree [Adansonia Grandidiera], and This is a tree [Wollemi Nobilis].

This is a Wollemi Pine. It’s the only living species left in the Wollemia genus and it’s potentially up to 200,000,000 years old . Not this one specifically, but the species, Which is to say it’s first appeared [roughly] 150,000,000 before trees like oaks first appeared(Hipp et al., 2020; Kremer & Hipp, 2019). Which is to say the Stegosaurus and the Tyrannosaurus Rex came into existence and went extinct between the formation of this tree and this tree.

You see, the word tree is not so much like mammal or fungus which characterize a group of similar species. Tree is more of a strategy or a term like four legged animal, which can contain some mammals but not say whales and some reptiles, but not, say, snakes. Tree is more of a strategy that some plants use to survive. Generally, however, we call something a tree if it is, a, a plant, b, has a woody stem or trunk, c, has growth rings, and d, is big enough. So trees are really any plant that uses a similar strategy to survive and thrive.(Gschwantner et al., 2009; (PDF) The Meaning of “Tree,” n.d.)

Just like how different animals find having four legs to move around beneficial, different plants develop strong, woody trunks that allow them to grow higher than other plants around them, helping them compete for sunlight. For a lot of the same reasons that the trunks of trees are really good at growing tall and supporting a canopy of leaves, they’re also really good to make stuff from. Evidence uncovered in Zambia in 2019 suggests that humans have been working with food for hundreds of thousands of years.(“(PDF) Evidence for the Earliest Structural Use of Wood at Least 476,000 Years Ago,” 2024) So let’s have a look at what’s going on.

How wood forms in trees

This is a chunk of a log, a chunk of a tree, and here you can see where the tree first started growing up as a sapling and then of course, all the way out here, you can see the outside of the bark of the tree.

But it’s in this spot here between the wood and the bark where a lot of the action is happening, a lot of the growth occurs in a tree. This is called the cambium, and it’s what’s referred to as a meristem, or a collection of unspecialized cells that have the capacity to divide and create all the types of cells that are needed to make the trunk of this tree. Some of the cells in the cambium will divide and and form on the outside. These will become the bark or the phloem. They protect the tree, but they also transport sugary sap from the leaves down to the roots. (Becksvoort, 2015; Déjardin et al., 2010; Hoadley, 2000)

And then of course there’s all the cells that are formed on the inside towards the center of the tree. This is where we get wood or xylem cells in all plants. These xylem cells both provide structure to the plant, but also move a watery material from the roots up to the leaves. Just after these cells are formed, the majority of them will die and become hollow, allowing them to become pathways for sap. But only the newer cells still transport sap like this.(Spicer, 2005)

For this reason, this part of the wood is referred to as sapwood. It is often paler and less durable than the denser heartwood of the tree because most of these cells are empty. As the tree gets older, some of the remaining living cells in the wood called parenchyma cells will eventually(Ma et al., 2023; (PDF) Heartwood Formation and Natural Durability - A Review, n.d.; Spicer, 2005). And when they do, they explode, as I was told by Hiroshi Yamaguchi, and send out a series of minerals from the soil and secondary metabolites that the tree has made. These other materials, sometimes referred to as extractives, will fill the cells of the heartwood and the cell walls, making it denser and more durable, and often give it unique properties such as increased resistance to microbial or fungal threats, help the tree fight off rot or insect invasion, or affect the colour and the smell of the wood(Rowell, 2005).

Some of these parenchyma cells are known as rays, and you can actually see them really clearly on this piece of oak. There. They form pathways from the heartwood outward to the cambium of the tree, and they transport materials, metabolites, and other things that the tree trunk needs inward and outward as opposed to upward and downward(Becksvoort, 2015). They will actually be part of the food storage network of the tree and they’ll also help protect the tree if it gets damaged by pushing out resins and saps to seal and protect the outside of the tree. So, because trees are not all the same, the woods that they create are not all the same.

‘Softwoods’ and ‘Hardwoods’

And so, to explore that in a little bit more depth, I’ve decided I’m in a workshop. I might as well make something. So I’m gonna make a small set of drawers, but I’m gonna use four different timbers to make it. I’ve got here two softwoods, Douglas fir and Australian cypress pine, and I’ve got here two hardwoods, a nara and ebony. For those of you who’ve been working with wood for a while, you’re probably aware of this, but these words, softwood and hardwood, they’re bad terms.

So softwoods are not necessarily all soft. This Australian cypress pine for instance is one of the hardest timbers in the world. And hardwoods are not necessarily all hard. The famous example of that being balsa wood, which, you know, you could crush it with your fingers. The term softwoods applies to timber that comes from gymnosperms, plants with seeds but no flowers, such as conifers, trees with cones like pines, spruces, and firs.

The term hardwoods applies to timber that comes from angiosperms, or plants that have flowers. It includes things like oak, maple, elm, walnut, and ebony. Now you might be asking yourself, why would having flowers make such a difference to the type of wood a tree has? And that’s a really good question. It’s one I had as well, and so I dug into it a little bit, and it turns out that it’s not so much that having flowers affects the type of wood a tree has, but that when trees with flowers started forming wood, they did so in a different way than trees that didn’t have flowers. (Sauquet et al., 2017)

To explain this a little bit better, we’ll have to go back in time to before trees even existed. Did you know that the earliest trees ever discovered were neither hardwoods nor softwoods? They were actually more closely related to ferns and reproduced by spores. They were called Archaeopterus (“(PDF) Archaeoperis Is the Earliest Known Modern Tree,” n.d.), and they would grow to six meters or potentially 20 feet tall. This Devonian era tree didn’t contain wood as we would understand it today, but some fossils from this time do show that wood does start to appear mostly in the root structures of some plants.

And while there were some woody trees with secondary cell walls like we’ve discussed before, it would really be our softwoods, our gymnosperms, that would start to form woody trunks in the way that we understand them today(Gerrienne et al., 2011). And the system that they would use would be relatively simple, but very effective.

Gymnosperm wood and xylem cells (softwoods)

Most of the xylem cells in a softwood are called tracheids. They’re the vertically oriented cells that both support the tree vertically, but also transport a lot of the sap up through the tree. You might be imagining in your head a cell that’s like a bubble of biological bits.

And you may be asking, how does sap actually move through that bubble? When the tracheid is formed in the cambium, it is a kind of bubble of biological material with the nucleus and the mitochondria and all that good stuff. But it also develops a super thick cell wall structure around the initial cell wall you might be familiar with. This cell wall is made up of long strands of cellulose and hemicellulose and a material called lignin (Mills & White, 2012; Rivers & Umney, 2003). They work in a matrix system similar to carbon fiber or fiberglass, with the cellulose and hemicellulose functioning as the long fibers and the lignin functioning as the resin that holds it all together.(Rowell, 2005)

It’s got this funky long rectangular shape as well, and it also has these holes in its sides at the top and the bottom, here and here. Once these layers of cell wall are formed, the whole cell becomes quite firm and strong, and the cell inside dies. And the thin interior cell wall and all the cell bits like the nucleus and whatnot flow out, leaving this solid shell ready to transport material and hold up a whole tray. So with a lot of these softwoods or gymnast firms, early in the growth season when it’s wetter, they tend to grow larger cells with bigger lumens or passageways inside so they can transport more of that water. And then later in the year, they tend to grow denser, smaller cells with a lot more lignin around them.(Caneva et al., 2008)

You actually see very clearly on the end of this piece of Douglas fir, where you’ve got these very dark lines and these very pale lines. Those pale lines will be the early wood, the early part of the growth season when it’s really wet and those cells have grown really large and open and there’s a lot of empty space in there comparatively. And then the darker bits will be where the cells are a lot denser and there’s a lot more lignin. This is the late wood or the dry season. These larger cells, this pale area, this one also tends to be a lot softer and so as the wood ages, if you run your finger across it you might notice ridges where the softer wood, that early wood, has shrunk because of those open cells and that softer material and that harder denser cells and that softer material and that harder denser late wood has stayed quite strong and firm.

Now this isn’t the case with all softwoods, this is very common with a lot of the softwoods we are familiar with, like pines and firs and spruces, things that, like where I grew up in New England, are really common. But here in Australia, we don’t necessarily always have distinctive wet and dry periods. This Callitris, for instance, is an Australian tree, and it doesn’t have that same differentiation in softness and hardness between the early wood and the late wood. Both of them tend to be quite dense because this grows in a very dry area all the time, so all the cells tend to be fairly dense and small. And then some woods like Cowie, which is an Erycaria, you don’t notice really much differentiation in them at all between early wood or late wood, because they don’t really have a wet season, dry season growth difference.

They tend to grow fairly consistently throughout the year. But despite their differences, they’re all still gymnosperms, and they all still have that same tracheid cell structure.

Angiosperm Xylem Cells (Hardwoods)

Our hardwoods on the other hand, are angiosperms, are flowering plants. When they came along, they did things a little differently. My understanding is that all conifers rely on gravity and wind to disperse their seeds.

So it would have to be another group of plants that would take advantage of this idea. And they would do so with the invention of the next great idea in plant evolution. The flower. And with these new flowering plants, we have our first angiosperms. Now evidence suggests it wasn’t a tree or a conifer that grew the first flowers, it was probably a grass or a wetland plant. (Janssens et al., 2020)

So when those new flowering plants or angiosperms first started forming trees with wood, they would do it in a slightly different way that was rather ingenious. Rather than all the vertical cells of the wood doing both jobs of adding structure to the tree and transporting sap, these hardwoods create more specialized cells, fiber cells, which provide support, and vessel cells, or pores, which transport sap. With woods like our oak here, they actually end up growing these big distinctive bands of pores at the beginning of the year. So, with our oak for instance, it loses its leaves at the beginning of winter and then at the beginning of spring it needs to grow new leaves again and so it creates these big vessels so it can transport as much sap up to leaves as possible to create new leaves. And then the rest of the year, it really doesn’t create any pores at all and so you have just this dense fibrous area.(Déjardin et al., 2010)

You can also see it if you look really closely at the end of the piece of wood, you have these areas where there are big open cells and then these denser darker areas where it’s mostly fibers without any vessels or pores at all. When woods form like this, with these distinctive bands of pores and then the rest of the year no pores at all, we call that ring porous. On some other hardwoods, you might find that there’s some big pores at the beginning of the year, and then it slowly tapers out as the season goes on. We call this semi ring porous. And on some others, there might be no difference in the variation between the vessels and fibers throughout the whole year. We call these non ring-porous. .(Becksvoort, 2015)

This is often in correspondence with the weather of the area, whether there are strong wet or dry seasons, and whether the tree loses its leaves or not. A lot of these hardwoods also end up with more pronounced rays, those parenchyma cells that go from the middle of the tree outward towards the cambium and provide storage of materials and a transfer of materials from the inner to the outside of the tree (Hoadley, 1990). For some reason, these hardwoods have developed much more prominent ray cells than in a lot of the softwoods. You can see it really clearly here on this oak like I showed you before, these really distinctive lines or pathways from where the inside of the tree would be to the outside of the tree.(Hoadley, 2000; Rowell, 2005)

And you can see that how that affects how it looks on a tangential cut with these distinctive lines or bands in this oak piece here. It’s really prominent in some other woods like lace wood or this beef wood here, and you can see on this particular cup how those parenchyma or those ray cells are cutting across the direction of the tree growing in a more perpendicular direction to the rest of the fibers and pores of the wood. But, I’ll talk more about a lot of that later on. For now, I need to clean this up. I need to get started making my project, but as I do I’d really like to go through each of the timbers that I’ll be prepping and talking about them specifically and also some of the aesthetic and visual choices that we can make with these woods, understanding them a little bit more clearly.

Douglas Fir and Wood Grain (The visuals of growth rings)

In Australia, this timber is often referred to as Oregon pine colloquially because it was a pine like species, a softwood, a conifer, imported from somewhere around Oregon. You commonly find it in the walls of timber frame buildings from the late nineteenth and early twentieth centuries where it looks like this. Now I get quite frustrated, somewhat frustrated, with the way that a lot of softwoods are referred to as pines when there are so many other types of conifers and softwoods from spruces and firs to cedars to araucaria and all sorts. The species is more commonly known as Douglas fir or Pseudotsuga menziesii scientifically, and they can grow between 20 to a hundred meters tall and up to five meters in diameter. They’ve also been known to live for well over a thousand years.

If we look at the end of this particular board, we can see that there are all the rings from the tree’s growth in this end grain. Now this is a softwood, so there are no vessels here. It’s just tracheids. This is a tree in the pinus family, and it grew in an area with a pretty strong wet and dry season. And you can see that here in the way it grows with these lighter, softer areas from the early season and then these darker denser areas from the later dry season. (Ruffinatto et al., 2015)

This is one of the reasons why I like to work with reclaimed timber. If this tree lived for hundreds of years, I like to respect it by trying to use the wood that comes from it for hundreds of years as well. Additionally, with these softwoods, that slow growth and density also increases its strength and durability. And apart from just being sentimental about the life of a tree, these rings have important decorative impact on the wood as well. You can see here how those rings are seen on the side of this piece of wood, and it creates a very specific visual effect.

On this piece of fur, that visual effect is a little bit different, and has to do with where in relation to the tree the piece of wood was cut.

Timber Grain and Dimensional Terminology

Here’s some terminology that’s helpful.

This is a generic tree trunk, and it’s different in different directions. We can draw one line going up and down, another line going inward and outward, and then we can form a third line perpendicular to that inward and outward line. This up and down direction we call longitudinal.

The inward and outward direction we call radial, And this other direction is called tangential. Longitudinal, radial, tangential. Now remember, these terms are in relation to a tree, which is a circular tubular object. So while the longitudinal direction is pretty straightforward, the radial direction is always describing from the center of the tree outward, where it’s cutting across these rings. So radial grain is always kind of across these rings.(Becksvoort, 2015)

But the tangential line is always 90 degrees or perpendicular to that radial line. So if that radial line is here, that tangential line is here. And if that radial line is here, that tangential line is here. I like to use these terms when describing what I see in wood because they’re somewhat simple, and they help remind me of the wood’s relationship to the tree and what that relationship is. Now, in traditional milling of timbers, there are a number of cuts of wood you can get.

If you take a log and just slice through it in the most straightforward way, you’ll get mostly what are called flatsawn or plain sawn boards. Most flatsawn boards will have tangential grain on their main face, which ends up looking a bit like this, with these sidebands and some of these mountains or crowns, as they’re sometimes called. But if you cut a log up like this, you get what we refer to as quartersawn boards or riftsawn boards. In some cases, different people refer to things by different names, which is why I like to use the terms discussed earlier. On these cuts, you’ll have both radial grain and tangential grain.

And on this one, you’ll have radial grain on all sides, which results in long straight lines aesthetically. There are in fact a lot of purely aesthetic as well as structural reasons. One might choose to use a particular cut of wood over another. For all of my drawers, drawer sides and drawer backs, I’ve chosen to go with this fairly straight grain structure this quarter sawn timber mostly for structural reasons because these pieces aren’t going to be seen. But for my drawer fronts they are going to be seen and so it’ll be a great place to talk about some of the aesthetic choices you might make of a cut of wood.

Cypress Pine and Decorative Choices

I’m making the drawer fronts out of a timber that is sold here in Australia as cypress pine, but its scientific name is callitris. It’s also a softwood, but it has very different properties to the Douglas fir. Because the design of our piece is really simple, with just proportion and shadow lines for its aesthetics, the choice of timber we use is pretty important and not just the species we choose to use but the type of cut we use as mentioned before. For instance this is the cypress pine piece that that I got from Among the Trees to work on for this project and cypress pine is it’s a very hard timber and as it dries it’s very prone to splits and cracks and it’s full of knots as you can see with this one. So even though this is a rather large board I had to make choices and where I could use it and it may seem wasteful to have taken it from the middle but I assure you I’m going to do things with these other sections.

But where in this piece of board we choose to take our timber from still matters. So with this one I found this section in the middle that I quite liked. Traditionally with a lot of drawers if you can get a piece wide enough you would make a drawer front here and here and here so that when your drawers all lined up stacked on top of each other they look like one wide piece of timber But there are other options that you can choose as well. In this case from this section here because of all these splits I found this bit here that I could take and turn and I’ll get rid of that one and I could slice up this way into four pieces. And those four pieces all have a relationship with one another in the tree so they’re going to have a similar look they’re going to have a similar colour and so I can get a similarity out of them but they won’t show one big piece of timber.

What I can do with them however I can potentially lay them out like this so that we got kind of a series. They all look relatively similar and they’ll all have a similar look across them. But I can play with this a little bit. I could say swap this one over this way. So now I’ve got a bit of a back and forth look with those pieces of timber.

Or if I undo that, I could maybe flip this one and this one over so that now these are a little bit like mirrors of one another, and they have kind of a a top and bottom, top and bottom kind of mirroring effect. This is often called book matching. When you cut through a piece of wood and open it up in this way like you’re opening up a book, and it creates that symmetrical effect. I could even then, if I wanted, take this and flip this one over so that now I’ve got this top one with a mirroring effect that way and this bottom one with a mirroring effect that way. All of these choices are yours to make and this is one of the great things about working with timber is that once you start looking at what the wood is offering you you can have a play with it and be very thoughtful about using the wood itself and the material it is to create all sorts of visual effects.

We’ll talk loads more about this later on when we talk about veneers, but for now I’m really happy with this one, and I think this is the way I’m gonna go forward.

Narra and ‘Figure’

For the case of the cabinet, I’m using Narra wood or Pterocarpus indicus, also sold as New Guinea Rosewood here in Australia, although it’s not related to rosewood at all, and it’s predominantly native to The Philippines, where it’s The Philippines national tree, as well as Vietnam, Indonesia, India, and a number of other countries in the Southeast Asian region. Unlike our fir and Cyprus, our nara here is a hardwood or an angiosperm, which as you may remember means it’s a flowering plant. And it’s actually got some really beautiful golden yellow flowers that bloom in late April and early May. Because it’s a hardwood, that means it’s mostly made of, fibers and vessels, and you can actually see that pretty clearly when you look closely.

The pores are these long chicken scratch looking holes in the timber. Those are not imperfections. They’re part of the wood. The rest of the wood you’re seeing is those fibrous cells. While the cell type and the porosity of the wood will definitely impact how it looks, There are other ways in which the tree grows that will also impact the way a piece of wood that comes out of that tree will look.

One of the ones you’re probably most familiar with is knots. We saw them in our cypress pine. They’re a place where, when the tree is growing, it starts to grow branches, And then as the tree gets older, the wood subsumes those branches. But when you cut into it again, you start to see that juvenile wood of those early branches. Here, you can see what a knot looks like in the radial grain, and here you can see what it looks like in the tangential grain.

And then, of course, if you’ve got, say, a tree that’s that’s growing in kind of a bulging in and out, when you cut through that, you’re gonna get a very particular visual effect in the wood where you’ve got bits of the grain or the pores coming towards you and bits of the grain moving away from you. And as light hits those whether it’s going into the ends or across the ends it’s going to reflect back differently and create a different visual effect. You actually see it quite clearly here on this piece of eucalypt where we’ve got a really obvious wiggle back and forth where that happened in the tree. And then what’s really interesting about that is that’s how it looks here, But then when we rotate this to the side, you can see that there’s kind of a ripple effect that tore out really terribly when I was painting it, but a bit of a ripple effect that can appear in that board. We get a similar kind of light and dark pattern in our Nara here.

We’ve actually got a light and dark visual effect, but it’s not because of a ripple. It’s kind of in these vertical bands through the wood of light and dark. Then if I turn them around, they actually change which is light and dark, and that occurs not because of a bulging ripple in the growth but because of alternating twists in the way the tree grew. So when I was in Norway and we were looking at the pines there, they told us that in the first half of the tree’s life they would twist or spiral to the left and then in the later half of the tree’s life they would spiral to the right and this would create a kind of stability in the tree as it got older. This is not a unique property to just these pine trees and in fact some trees will spiral much more consistently or more dramatically than others.

Certain trees in some years of their life in that cambium, they’ll create cells that are starting to spiral in one way and then the next growth season or every few years they’ll spiral back the other way. And when this happens you get what’s called an interlocking grain where some of the fibers are going this way and then the ones next to it are going that way and the ones next to it are going that way and it creates a really beautiful pattern in the wood.

Ebony

Thinking about trees brings us to the last word of our project. This is commonly known as ebony, but I don’t actually know what species this piece is in particular, or most of these pieces. Ebony refers to a dark dense hardwood with this deep black colouring and there are many species mostly within the diaspora’s genus which can create this type of wood.

Because of its desirability in decorative objects and musical instruments in Europe and America and China, this material has been largely harvested and deforested in many of its native homes. Countries like Sri Lanka, Indonesia, Madagascar, and others are now severely restricting, if not outright banning, the forestry of these trees (Jahanbanifard et al., 2019). You know, I said that I don’t actually know necessarily what species of tree this came from? Researchers are now trying to find better ways to figure that out so that they can better enforce some of those restrictions because there’s still a great concern about ongoing deforestation and illegal logging that continues to today due to foreign demand specifically. (Deblauwe, 2021a)(Zhang Ke & Zeng Zhi, n.d.)

But let’s take a moment and have a look at some of the properties of this wood of this tree that have caused it to be so desirable.

Why is it so dense, and why is it the colour that it is? To do this, I think this is a really good time to look back at some of the things we’ve discussed so far in this video and do a bit of recap of what we know about trees and apply it to to this timber.

Ebony and a Wood Formation Recap

As a tree grows, new wood is formed out here in the cambium. These outer cells die and are hollow to allow watery sap to travel. In soft woods, all the cells transport sap.

And in hardwoods, only the larger vessels transport sap. But these xylem cells are hollow and dead. In trees with regular wet and dry seasons, you often get really distinctive rings of growth with early and late woods, like our Douglas fir, which will have different densities.

Ebony crassiflora, or Gaboon ebony, on the other hand, grows in a rainforest without much of a consistent cycle, so there aren’t really the same distinct rings or variation in its growth, adding to its consistency as a material. Additionally, crassiflora is a shade loving tree. It does well under the canopy of large, older trees and will grow rather slowly and densely in this environment. (Deblauwe, 2021b)

The other cells in the sapwood area are called parenchyma cells. That’s what the rays we saw in that oak and beef wood were. While the tree is alive, these parenchyma cells in the sapwood are also still alive, and they build a network vertically and horizontally, moving hormones through the tree and transporting protective sap and resins to the outside of the tree if there’s damage. They are a communication and materials transfer network moving more than just sap.

Now, as the tree gets older, these parenchyma cells will eventually die. They are, in fact, designed to die. And when they do, they don’t just go hollow and become useless. They do a lot of interesting stuff. Right here at the interface between the heartwood and the sapwood, it’s the way these parenchyma cells die that creates the heartwood and determines a lot of its qualities.

One thing I love about heartwood formation is that there’s still actually a lot of research being done into it. It it wasn’t until, like, it wasn’t very long ago that there was a theory some people had that because trees don’t poop((PDF) Heartwood Formation and Natural Durability - A Review, n.d.), the heartwood formation is the tree putting its waste into the core of the tree. And it wasn’t until like the last twenty years or so that more in-depth research has been done into this process to tell us exactly what’s going on, and that heartwood is not just tree poop. When the parenchymas die, they send out a lot of different secondary metabolites and organic compounds into the wood cells around them, filling the hollow lumens and cell walls of the fibers, vessels, or tracheids of the wood. These other materials can be antimicrobial or antifungal, helping the tree fight off rot or insect invasion.

They can be dense bulk that makes the wood stronger and harder. They can add colour or a wide range of other qualities to the wood. And it’s largely these other materials in the heartwood that will give different timbers their colour, durability, and some other interesting qualities, including the way they smell when we work with them. And that’s unique to each and every species, as well as the conditions in which each individual tree grows.

Black walnut is a great example. We know now that when the parenchyma die, they release a particular molecule into the heartwood that causes the colour change inside of that wood. And we also know that the amount of heartwood each individual tree varies even on a plantation where all the trees grow in the same condition next to one another.(Dehon et al., 2002; Woeste & Beheler, n.d.)

The variables of black colour in Ebony

What’s really interesting with ebony though is that you would assume that the black colour of ebony would be due to that same process of parenchyma cells dying, releasing something, and changing the colour of the wood. But last I read, and as far as I could find, we’re still not entirely certain why ebony wood turns black. In fact, not all trees that can produce black wood will(Deblauwe, 2021b; Jahanbanifard et al., 2020; Ma et al., 2023).

Many times people don’t know whether a specific diasporus tree has black timber inside it until they’ve cut it down, it’s fallen over, and they look at the stump or the end of the tree itself. Many times they’ll be hollowed out in the core, and sometimes they’ll be streaky or with no black timber at all. You can imagine that this greatly impacts forestry because if only one in every 10 trees, for example, produces solid black timber inside then you’re cutting down way more trees than you need to get the timber you want.

Wood: It Comes from Trees

And that’s all part of why I wanted to include ebony in this video. I think it’s really easy to say look at this knob and forget that it’s wood, that it came from a tree.

This, because of how dense it is, how glossy it can be, how consistent it is, can look more like a plastic or a metal or a mineral, but this is from a tree. This is from a tree in a rainforest that grew in shade, that grew slowly and densely creating very tight grained timber with very few vessels, and because of either a reaction to environment or soil or pests, it created this particular black colour, a colour that has been prized internationally for thousands of years, and because of that the communities where this tree came from and the forest where this tree came from have been impacted by foreign influence. This particular knob came from a harpsichord key, from a harpsichord that was being thrown away. It was found on the side of the road here in Sydney. And I think knowing everything we know about this tree and its history, it’s a shame to see this wood end up in landfill.

So that’s why I’ve chosen to use it in this case. But I think it is very important to be aware of, not just with ebony, but with all woods and all materials, what that material is and where it came from, and be thoughtful about how you use these materials and whether or not you should or shouldn’t. I’ll leave that choice to you, but I think it’s important to remember that wood comes from trees, and that means a lot. So yeah, wood comes from trees. We all know this, but I do think it’s easy to kind of forget what that means sometimes.

For instance where I am I can go to a hardware store and I can buy timber in dimensions. I can buy it in board feet, or I can buy two by fours. I can get soft woods or whatever in this much stock at this much size, and it gives this impression that this is just a material, a consistent material that you can get over and over and over again. But it’s a wood that comes from a tree, directly from a tree that grew in different places at different times, and that all impacts what it is as a material. We know, for instance, that you can have the same species of grape, but if it grows on that vineyard or that vineyard, it might taste different, and even if it grows in this year versus that year, all of the factors of where it grows are going to impact how it tastes.

Trees and wood, as far as I’m concerned, are very similar, so it’s worth paying attention to the wood that you’re working with and thinking about it as a material that came from a tree. At least that’s helped me a lot, it’s helped me understand and appreciate this material, and particularly how it looks. I’ve got all my pieces mostly ready to go I need to start sanding and scraping and planing them back to get their surfaces ready before glue up, and we’ll be doing that, and I’ll be going through that in the next video. But we’re also gonna be talking more about how light interacts with these surfaces to create the visual effects that they have that we looked into a little bit earlier in this video. So I hope you see me there. I hope you join us. Thank you very much.

Credits roll

Thank you so much for joining us. I’ve really enjoyed putting this video together. I’ve learned a lot about wood while doing it.

If you enjoyed it and you got a lot out of it, fantastic. You can check out what we’re trying to do over on our Patreon. There’s something about that somewhere around here. And I really hope you join us in the next video as well where we’re talking about light, we’re gonna talk about colour, and we’re gonna talk about surface prep, sanding, scraping, planing, and there’s so much more after that. We’re gonna go into durability.

We’re gonna start actually working with finishes. I really hope that you join us for all that. I’ll see you there.

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