This page answers the questions that come up most often and defines the words used everywhere else on this site. The left column links to full pages. The right column gives the short answer. Below both of them is the working vocabulary of the mill: what the parts of a log are called, what the different cuts are called, and what the tree itself leaves behind in the wood.
Trees that developed naturally over long periods of time, without modern forestry management.
A tree number uniquely identifies one documented tree and ties the blog post, the video, and the map pin for that tree together.
Because nothing about a tree is settled until it is opened on the mill. What comes out of a log is known after it is sawn, not before.
No. A pin means a tree was found and documented. Some of those trees will not be worth milling, and the map does not track what has already gone.
No. OGM saws its own documented trees and does not take in outside logs.
The actual work: the tree on the ground, the cuts, and what the log turned out to be once it was opened.
Every one of these is a word that gets used loosely somewhere. This is what it means here.
A squared timber produced early in breaking down a log. Squaring the log creates flat reference faces, which makes every cut after it more predictable. A cant is not an end product; it sets the conditions for accurate milling, and a sawyer with his own mill can buy one and finish it his own way.
A large section cut straight through a log with the outer shape left on it. Flitches are often kept in order so the boards from one log stay together as a set.
A board cut the full width of the log, usually thick, usually with the natural edge left on both sides. A slab keeps the shape of the tree instead of being squared to a dimension, which is why it is the form most often asked for out of a large old tree.
The natural outside edge of the tree left on a board instead of being sawn straight. The bark may stay on or come off; the shape underneath is the edge.
A section of wood prepared for turning on a lathe. Blanks are cut oversized so movement can be taken up during drying and rough turning.
Lumber cut to thickness but not surfaced. It is left rough so it can dry properly and be sized last, by whoever is going to use it.
The unit rough lumber is measured in: 144 cubic inches, or a piece one inch thick, twelve inches wide, and twelve inches long. Thickness counts as sawn, not as surfaced. It measures volume, not surface area, so a two-inch board covers half the area a one-inch board does for the same board footage.
Boards cut straight through the log so the growth rings meet the face at a low angle, roughly 0 to 30 degrees. Most furniture is plain sawn. It yields the most from a log and it is where cathedral grain comes from.
Boards where the growth rings stand near 90 degrees to the face. True quarter sawn comes from right at the heart, left and right of the pith and above and below it, so a log gives up only a few of them. They are the most stable boards in the tree and they look different from the face, the edge, and the end.
Boards where the rings meet the face between roughly 30 and 60 degrees. Rift sits between quarter and plain: a straight, tight, quiet grain line without the ray fleck. A great deal of wood sold as quarter sawn is actually rift.
The arched, pointed pattern that shows on the face of a plain-sawn board. The growth rings stack up the trunk as a series of cones, and a saw passing across them at a shallow angle opens those cones into arches. The peaks point toward the top of the tree.
Flat, shining patches lying across the face of a true quarter-sawn board, strongest in oak. They are the medullary rays — sheets of cells running outward from the pith — split lengthwise instead of cut across. Fleck only shows when the rings stand near square to the face, which is why the few quarter-sawn boards in a log are worth pulling out.
Any grain pattern that is not plain straight grain: curl, fiddleback, quilt, birdseye, crotch. Figure is the tree’s own history showing in the wood — stress, injury, the way it carried a limb. It is not something that can be ordered by species.
Two limbs, or two trees, growing into contact until the bark between them is crushed out and the wood fuses into one continuous grain. A natural graft. In a board it reads as two grain patterns running into each other and becoming one.
Bark trapped inside the tree where two stems grew hard against each other and never fused. It leaves a dark seam running down into the wood. In a standing tree it is a weak point, and in a fallen tree it is often where the split started.
Anything the tree grew around and closed over: bark, a limb stub, a nail, wire, a stone pressed into an old wound. Old trees on old ground carry more of them than young trees do, and an inclusion is found with the saw, not before it.
A rounded growth on a trunk or a root where the grain has gone into a knotted, swirling mass instead of running straight. Burl is cut for figure, not for structure.
Wood the tree grew under different stress to hold up a limb or to right a leaning trunk. In hardwoods it forms on the upper side and is called tension wood. It moves badly once it is sawn, and it is a large part of why limb wood is unpredictable.
A separation that follows a growth ring, splitting the wood in a ring rather than across it. Wind shake comes from a standing tree being worked back and forth for years. It is usually invisible in the log and shows up when the piece is opened.
A split that runs across the rings, opening as the outside of a board dries and shrinks faster than the inside. Checking is a drying event, not a storm event.
Colored lines and zones left in the wood by fungus that has started to work on it. Early spalting is prized and late spalting is rot. The difference between the two is time on the ground.
Gray, green, or brown streaking left by minerals the tree drew up out of the ground. It is not decay and it does not weaken the board. In old oak it is common, and it is sometimes the reason a board gets chosen.
Wood that still holds the water it had in the living tree. Green wood cuts easier and weighs a great deal more. Nearly everything a board is going to do — shrink, cup, check, twist — it does on the way down from green.
Stickered under cover and left to come down to the moisture of the air around it. It is slow, it is the least violent way to dry old wood, and it costs time rather than fuel.
Heat and airflow used to take moisture lower than the outside air will take it, and to hold it there. Every step of drying is work, and work carries a price.
