A carving goes well or badly depending on the direction of the cut relative to the grain. The same knife, in the same wood, leaves a glossy facet in one direction and a torn, furry patch in the other. Learning to see the grain before cutting means that the knife is always working in the direction the fibres want.
What grain is
Wood is a bundle of long tubular fibres, running along the trunk of the tree. The grain is the direction of those fibres. On a board it runs roughly the length of the piece, but it is seldom perfectly straight. The fibres slope, curve around knots, and change direction in the crook of a branch. A knife cuts those fibres either by slicing along them, where they part cleanly, or across their ends, where a thick bundle is cut at once.
Seeing it on the surface
The lines on the face and edge of a board show the direction. On the edge, the grain lines run at a slight angle to the surface. Think of the lines as rising or falling along the board. A cut that travels in the direction the lines rise, with the knife going from the lower end to the higher, is going with the grain. A cut in the opposite direction lifts the fibres ahead of the blade, and causes tear-out.
A practical test is to make a short, shallow cut in the waste area and look at the surface. A glossy, smooth result means that direction is right. A rough surface or a chip that splits ahead of the blade means reverse it.
With and against the grain
Going with the grain, the fibres lie under the blade and support each other. The shaving curls off smoothly and the surface shines. Going against, the point of the blade wedges under fibres and lifts them. Splits can run ahead of the cut, well past where you meant to stop.
Near the end of a cut, the blade approaches a different orientation. If the cut runs downhill to the end, the support of the fibre at the end of the cut vanishes and the wood may split out. Make a stop cut at the end of the intended cut, so the following cut ends at the stop and does not run on. The cuts database lists the stop cut and its use.
End grain
The end of the block, where the growth rings and fibre ends show, is hard to cut because the knife must sever the fibres across. Cuts into end grain need more force, and leave a rougher surface. Reduce the force by taking thinner shavings. On a figure, such as the top of a head, work from the end toward the middle in short cuts, turning the piece so the blade is always cutting downhill.
Changes of direction
Grain often reverses along a piece. On a round form such as a head, the grain runs up one side and down the other, so the cutting direction must change. Carvers work from the high point down in each direction: from the crown down toward each side of the face, from the nose toward the forehead and the chin. The same applies to an arm, a leg and a tail.
Branch joints and knots are places where the grain swirls. Cut lightly and from several directions, with shallow cuts. Use a finer tool for these areas, or work them last.
Wood choice and grain
Some woods forgive a wandering grain. Basswood has a very even, fine grain and cuts cleanly in nearly any direction, which is why it is the carver's standard. Butternut is similar. Oak, ash and other open-grained hardwoods have large pores, and the walls tear easily across the rings. The carving woods database lists each species with its grain and ease of carving. The database entry for pine notes the contrast between soft spring wood and hard summer bands, which makes the direction matter more.
Dealing with tear-out
If a patch has torn:
- Stop and look. Find where the fibres rise, and where they fall.
- Turn the piece around and cut back toward the torn area from the opposite direction.
- Use lighter cuts, taking a thin shaving at a time, with a keen blade.
- Use a skewed blade, slicing with a drawing motion across the surface, so that the edge shears the fibres.
- Finish with a scraper or sandpaper if a slight fuzz remains.
A dull edge makes everything worse. Keep the knife stropped and check for a burr that catches on the wood.
Reading a blank
Before you draw the design, look at the blank. Put the long axis of the carving along the grain, since long thin parts, such as a wing or a neck, will be much stronger if the grain runs the length and does not cross it. A cross-grain arm of a figure breaks at the shoulder with the slightest knock. Place delicate features in the spot where the grain is straight and clear of knots.
Summary
| Situation | What to do |
|---|---|
| Grain rises toward the cut | Cut with it |
| Fuzz or tear | Reverse direction |
| End of a cut | Stop cut first |
| Round form | Work downhill from the high point |
| Knots | Shallow cuts from several sides |