How do you figure out the grain of a fabric for sewing? Why do you need to know??

Put in simple terms.. Make a small snip at the salvage edge ( the finished edge ), Tear the fabric from one side to the other. Ca not do it? Make the snip & tear further down the salvage edge. Keep doing this until u can tear from one salvage to the other. THEN, ur fabric will be 'on grain'.The print on the fabric has nothing to to with the 'grain' If ur fabric is not 'on grain' it will stretch (for a lack of a better term) in the wrong direction..This should be step ONE in any garment construction!

When the store cuts the fabric for you, the selvage edges r usually folded together. They cut across the selvage ends to cut ur fabric from the bolt.

As was said above, knowing the lay of the grain can be important for fabrics with a nap (velvets) or one way patterns. And it can be important because sometimes u will lay pattern pieces a certain way across the grain to gain all the strength u can from the weaving.

When making clothes it is also important because how u lay the pattern pieces on the grain affects how they flow & stretch when u sew them together.

Pattern pieces have long arrows on them that should go parallel to the selvage edges. The way I learned to pin patterns is to start pinning one of the sides of the long arrows, measuring how far it is from the selvage edge, then measuring the same distance up & pinning the other end of the arrow there. Then pin the edges of the piece down. It is a pain sometimes but it helps ensure that the fabric all hangs nicely when you're finished sewing it together.

Here is a direct quote from my quilting book.
''When fabric is produced threads r woven in two directions, creating a length & a width. This is called the straight of grain. If u cut diagonally ac cross the grain (in triangle pieces) u r working on the bias. Bias edges must be sewn & pressed carefully, since they stretch easily. The long finished edges of the fabric r called the selvages. Always trim off the selvage edges since they can cause distortion of the block & r difficult to hand quilt through.''

Depending on what u r sewing the block comment probably wo not apply. However, the selvages r plain white or the same color of the base color of the fabric, & usually have printing on them. If u r sewing clothing this would not be attractive in use. The length of the grain goes along the selvage, while the cross grain goes from selvage to selvage. The bias of the grain would go from opposite corners (IE top left to bottom right) of the fabric.
Why it matters is the strength of the grain. Your length grain is going to be stronger & stretch less then ur cross grain. The bias is the weakest grain since it cuts across both grains.

Good luck & I hope u enjoy ur sewing!

The selvage is just the side end of ur fabric. If u r using a pattern, it will be the open side of ur fabric when it is folded in half. The grain, another word for the nap, is the direction the material flows. You may have noticed on velvet or corduroy that it looks one color when u rub it one way & looks darker or lighter when u rub it back the other way. You want to cut ur pattern so that it all goes one way, usually the smooth way running down towards the bottom. Some fabrics also have a design, such as floral, or stripes, that need to be cut in one direction. If u lay the pattern piece for a pocket or collar wrong, u will have a pattern running different from the rest of ur outfit. If u do not have to worry about the design & cannot feel a difference in ur fabric when u rub ur hand up & down it, u probably do not have to worry about it. Most patterns have a ''lay-out' that will show u how to cut out ur pattern, based on the width of ur fabric. If u follow the lay-out & cut ur pieces in the direction it shows, u will be alright.