Artisans tend to pick wood with beautiful grain because it allows them to create appealing products. However, prominent wood grain carries the risk of splintery saw cuts and tear-outs that can ruin the entire project. Taking the time to figure out the woodgrain guarantees top-notch results.
You should follow the grain when working on wood. Always pay attention to the orientation of the woodgrain relative to the cutting blade to avoid tear-out. Proper grain alignment improves the appearance and joint strength while working against the grain causes wood to chip and splinter.
The rest of the article will explore topics related to the question in detail, including how wood grains are formed, types of wood grain, and how to judge grain direction on wood.
How Do Wood Grains Form?
Underneath the bark, a tree comprises two layers – inner and outer layers – each with distinct characteristics.
Sapwood is a moist, light, living layer that’s next to the bark. It comprises a series of tubes, xylem, and serves as a pipeline for the tree to move water and nutrients to the leaves from the roots.
Heartwood is the more rigid and much darker inner layer inside the sapwood. It comprises dead xylem tubes clogged with resin or gum and, as such, no longer works. Heartwood is the older part of the tree, which dies off as new tree sections grow around them.
Heartwood won’t decay if it is surrounded by new growing sapwood. Instead, they get stronger as the dead tree fibers are bound tightly by lignin, making the wood strong and hardy. Because of the tightly packed dead fibers, heartwood produces the best timber. It doesn’t shrink much on drying because it contains less moisture and isn’t susceptible to fungus.
Trees have an exciting growth cycle that entails forming new cells each year and creates annual growth rings. Trees begin their growth cycle in Spring by forming many cells with thin, light-colored cells, which form the light section of the growth ring.
A tree’s growth rate slows down as Summer ends, which results in the formation of smaller cells with thicker walls, also known as summerwood. This change creates the darker sections of the growth rings. The slowed growth rate and formation of thick-walled cells allow trees to prepare for winter when the cells remain dormant. In Spring, the growth cycle begins afresh.
Wood grains are visible when a tree trunk is cut vertically to expose the xylem tubes’ patterns. The type of grains visible on a piece of wood depends on how the miller cut the wood during harvesting.
Here’s a video showing the most popular woodcuts in woodworking:
There are four main cuts of wood, each giving the wood a distinct look.
- Live Sawn. It’s the most cost-efficient way to cut logs into planks as it produces the least amount of waste. The log is cut lengthwise in one direction to create planks without changing its orientation. The resultant wood has a rustic look because much of the log’s characteristic pattern is visible.
- Plain Sawn. This cut of wood has a distinct sawing method that produces minimal waste. The log is rotated 900 after each cut, which changes the orientation of the growth rings. Plain sawn cuts create the cathedral or flame wood grain pattern.
- Quarter Sawn. The cut entails dividing a log into quarters then cut each of the four pieces using the live saw cut. This method puts the annual rings at between 600 and 900 to the face of the plank. The results in a radial wood grain pattern but produces a considerable amount of waste wood.
- Rift sawn. This method entails cutting planks perpendicular to the growth rings. The cut produces a linear grain pattern, which gives the wood a modern look and is popular with maple and oak species. This sawing method is most wasteful and produces planks that are less than four inches wide.
Types of Wood Grain
Woodgrain refers to the pattern, texture, or direction made by the fibers that make up a wood piece. The following are the different types of wood grain:
- Straight grain. The fibers in the wood run parallel with the vertical axis of the tree trunk.
- Irregular grain. The fibers run in an unpredictable and erratic direction from the tree’s vertical axis, such as around knots.
- Diagonal grain. These results when a tree with a straight grain isn’t sawn along the vertical axis.
- Spiral grain. These fibers spiral to the right or left side and result when a tree trunk gets twisted while it is growing.
- Interlocking grain. In such wood, each growth layer’s fibers are aligned in the opposite direction.
- Wavy grain. The fibers in such wood continually change direction, creating a wavy pattern.
Artisans use the terms fine, medium, and coarse grain to describe wood’s texture. It refers to the size of the wood’s pores. Large pores have lots of spaces between them, making for a coarse texture. Fine-grained wood has small, compact pores giving the wood a fine texture.
Burls refers to a deformed part due to an injury or stress to the tree during the growth period and are notable in furniture making because they produce fantastic grain patterns when cut.
Identifying Wood Grain
You must identify the type of wood grain before cutting, planing, or jointing. You produce outstanding results when the knives cut along the grain. Working against the grain causes the wood to split, chip, or leaves you with a jagged cut.
Cutting across the grain results in a crosscut, while cutting in the same direction of the grain is a rip cut. Matching rip and cross-cutting saw blades with the right wood orientation get you the best cuts.
Identifying wood grain isn’t an exact science since many factors affect the growth rings’ shape and size. These tips will help you identify the most common wood grain patterns:
- Look at the grain pattern. Some species, such as oak, walnut, and mahogany, have distinct grain patterns that jump at you. Identifying the grain helps you to figure out the orientation. Use a magnifying if the grains aren’t as pronounced. Coupling the different wood grain identification methods are the best way to go about this process.
- Feel with your hand. Running a shop rag or gloved finger on the wood’s surface can help you determine grain orientation. If you feel splinters or snags as you move the finger or the rag, you’re pushing against the grain. Going along the grain will feel smooth since the fibers that make up the wood grain point in the direction where you’re moving the finger.
- Check the corners. The surface adjacent to the face you wish to work on can give you a quick and accurate answer. Place the piece of wood in front of you and check the edge. If the grains on the edge of the wood trend upwards towards the right side, the grain moves from left to right.
- Look at the end grain. Reading cathedrals can be misleading because it’s easy to assume the grain runs towards the apex. That’s not always correct. Checking the end grain can clear any confusion. If the growth rings arch downward, the grains run the same way as the cathedral points. An upward-facing arch means the grains are running against the cathedral points.
- Do a cut test. Sliding a chisel or a cornering tool on the wood’s edge can help determine the grain orientation. If the wood splinters, you’re going against the grain.
Going against the grain is a grave mistake when working on wood because it can ruin the results and create weak joints. Growth rings and the type of cut a miller used to determine the wood grain pattern on a wood piece.
Learning to identify grain patterns makes for excellent results because it reduces splitting and tear-outs when scraping, planing, sanding wood. Visual inspection is enough to let you identify the wood grain and its orientation if you know what to look for.