Flatsawn, Quartersawn, Riftsawn: How the Cut Makes the Board

Two boards from the same tree can behave like complete strangers. One cups the first humid week; its neighbor stays dead flat for a century. The difference isn't the wood — it's the angle of the saw.

See how your species movesEvery species page lists tangential and radial shrinkage — the numbers behind everything on this page.

Picture the log as a set of nested cones — the growth rings — and every board as a slice through them. The only thing that separates flatsawn from quartersawn from riftsawn is the angle that slice makes with the rings. That one angle decides what the face looks like, how much the board moves, and what the yard charges you. Learn to read that angle and the choice at the rack becomes yours to make.

Three Ways to Open a Log

Log cross-section with parallel cuts straight through, top to bottom — **Flatsawn** Straight through, top to bottom. Fast, almost no waste — most boards meet the rings at a shallow angle.

Log cross-section split into quarters, each quarter sawn into boards across the growth rings — **Quartersawn** The log is quartered first, then each quarter is sawn so boards cross the rings steeply.

Log cross-section with cuts radiating from the center like wheel spokes — **Riftsawn** Every board on a radius, like wheel spokes — and the wedges between them are the waste.

Flatsawn: The Default

Saw a log straight through like a loaf of bread and you get flatsawn (also called plain-sawn) lumber. It's the fastest cut, wastes the least wood, and yields the widest boards — which is why it's what fills nearly every rack at every yard, and why it's the cheapest.

The look is unmistakable: those shallow ring angles paint big arching cathedrals up the face of the board, like a mountain range drawn in grain. The price for the drama is movement. A flatsawn board's width runs mostly along the rings — the tangential direction — which is where wood shrinks and swells about twice as much. Flatsawn boards move the most, and when they cup, they always cup the same way: away from the bark side.

A finished flatsawn board face with large arching cathedral grain patterns running up its center — Cathedrals: the flatsawn signature — each arch is a growth-ring cone sliced at a shallow angle. Photo: Bubba73, CC BY-SA 3.0, via Wikimedia Commons.

Quartersawn: The Aristocrat

Quarter the log first, then saw each wedge so the boards cross the rings at a steep angle, and you get quartersawn lumber. The face grain goes calm and straight — and in white oak and sycamore, the cut slices open the medullary rays — the ribbons that run from a tree's core to its bark — and they shimmer across the board as ray fleck. That flash is the signature of every Stickley sideboard and mission-style piece you've admired.

The behavior matches the looks. With its width now running across the rings — the radial direction — a quartersawn board moves roughly half as much as its flatsawn twin and stays flat while doing it. There's a reason old drawer sides, workbench tops, and anything that had to fit forever got quartered stock.

So why doesn't everyone buy it? The answer is yield: quartering a log means more handling, narrower boards, and more sawdust per board foot, and the price reflects all of it.

A sanded and oiled quartersawn oak surface with shimmering irregular ray-fleck figure across straight grain — Ray fleck on quartersawn oak — the medullary rays sliced open and catching the light. This is what the premium buys.

Riftsawn: The Straight Man

Rift-sawing aims every board along a radius of the log, like spokes on a wheel. The rings cross the face at a steady 30–60°, which produces the plainest, straightest grain a board can wear: an even pinstripe, no cathedrals, no fleck. Furniture makers pay the premium for one reason above all — a rift board shows that same quiet pinstripe on all four faces, which is why table legs are the classic riftsawn purchase. A flatsawn leg shows cathedrals on two sides and stripes on the other two; a rift leg matches all the way around.

Stability sits close to quartersawn — well-behaved in every season. The waste is drawn right into the diagram above — the wedge-shaped leftovers between the spokes. Riftsawn is the most wasteful cut there is, and it's priced like it.

An oak board face with fine, dead-straight, evenly spaced parallel grain lines and no arches or fleck — The rift look: an even pinstripe, no cathedrals, no fleck — and the same on every face of the board.

Reading the End Grain at the Yard

The yard doesn't always sort this for you, but every board confesses on its end. Look at the ring lines crossing the end grain and check their angle to the face:

0–30° (rings lying nearly flat) — flatsawn. Expect cathedrals and movement.
30–60° — riftsawn. Straight pinstripe faces.
60–90° (rings standing nearly upright) — quartersawn. Flat-staying, fleck possible in the ray-heavy species.

Close-up of oak end grain showing curved growth rings crossed by fine rays radiating from the center — Oak end grain up close: the growth rings sweep one way, and the fine lines radiating across them are the medullary rays — the same rays that become fleck when a quartersawn cut opens them. Photo: Friedrich Böhringer, CC BY-SA 3.0 AT, via Wikimedia Commons.

And because a flatsawn log still produces a few steep-ringed boards near its edges, a patient ten minutes at the rack can pull genuinely quartersawn boards out of a flatsawn stack at flatsawn prices. It's the closest thing lumber buying has to finding money on the ground.

One more term you'll meet: live-sawn (or through-and-through) — the whole log sliced like our flatsawn diagram and sold slab after slab, bark to bark. Each wide board contains all three cuts at once: quartersawn in the middle, rift beside it, flatsawn at the edges. European yards have sold oak this way for centuries; American sawyers are rediscovering it.

None of this makes one cut "best." Flatsawn is honest, handsome, and affordable; quartersawn buys stability and fleck; rift buys uniformity. What changes once you can read the rings is that the choice becomes yours — made at the rack, on purpose, instead of discovered later by a cupped tabletop.