Understanding grain direction is important because it can affect the costs, look, strength and durability of your woodworking projects. The direction of the wood's growth rings determines how much strength it has, which affects how well the piece will hold up over time. Grain direction has a lot of influence on your woodworking project. Things it will affect are:
The look and feel for your parts - especially when you have parts next to each other as in the picture below.
The number of sheets you will need for your project - If you have a specific preference for grain direction, it will influence how the parts will be nested and thus how many sheets you will need.
With more sheets, more costs are involved. Also, take this into account when specifying the grain direction.
Types of Grain Direction
Along the grain: This is the most common type of grain direction, and it's easy to identify. It runs parallel to the long sides of a piece of lumber.
Across the grain: This type of grain runs perpendicular to the face of your board (or other pieces).
Along and across the grain are most commonly used. Less frequently used grain directions are:
Diagonal grain: Like straight-grained wood, diagonal-grained wood also has its fibres running parallel with its width; however, they're oriented diagonally instead of horizontally or vertically like straight-grain pieces do.
Quarter Grain: Quarter-grained boards have their fibres arranged at 45 degrees from horizontal or vertical axes; they're technically half-quarters because they're cut halfway through each side before being planed flat again so that all four sides appear equal when viewed from above.
Marking Grain Direction
Marking grain direction is a simple task, but it's important to do it correctly. A great method is to use arrows, colours or rendering, but you can also specify the grain direction as text on the Cutr platform.
Arrows: If you're marking the grain direction on a part in your 2D or 3D model (or on a screenshot), draw an arrow pointing in the direction of each board's growth rings (the annual growth lines). This will help the production partner to produce the part in the right grain direction.
Colouring: If you have multiple pieces with different grains running in opposite directions, give each one a different colour so that they're easy to tell apart for the production partner. In the ‘Notes’ field, you can specify the grain direction per colour.
Rendering: An easy way to specify the grain direction in your 3D drawing is to apply a ‘real’ material to it with a grain. In this way, it is clear to everybody how the grain should go per part.
Text: You can also specify the grain direction in the text boxes on the Cutr platform when requesting a quote. E.g.
Drawer fronts: along the grain
Back panel: across the grain
Conclusion
Now that you know what grain direction is and how to mark it, you're ready to start using this information in your woodworking projects. You can use the same method of marking on all of your pieces or create a unique system for each one. Whether you're building furniture or making simple boxes, knowing which way the grain runs will help ensure that your project turns out exactly as intended.