Sewing: Fabric Grain

A confession: every so often I try to make something with less fabric that the pattern maker suggests. One time I made a pair of pants, and all I needed to do to make the pattern pieces fit the fabric was to slant them just a little teeny weeny bit! And that was all it took to end up with warped pant legs. Gravity rules! And gravity wanted me to follow the straight of grain!

The grain of the fabric is something that must be heeded when you are making something that is going to hang - a shirt, pants, drapes.

Before getting into this too deeply, let us defined some terms.

Here is a diagram showing a woven fabric:

In this diagram:

• The red lines show the lengthwise threads of the fabric.
• The blue lines show the crosswise threads of the fabric, the threads that are woven into and around the lengthwise threads.
• The selvages are the side edges of the fabric. Here, the fabric is generally woven very tightly. Selvages are strong.
• The horizontal black arrow show the lengthwise grain.
• The vertical black arrow shows the crosswise grain - it is at 90 degrees to the lengthwise grain.
• The diagonal black arrow shows the true bias - it is at 45 degrees to the lengthwise grain (which makes it also 45 degrees to the crosswise grain).

One of the demonstrations that I do with all of my sewing students is to get a piece of woven fabric, and do the following:

• Hold the fabric on the selvage, with your two thumbs about 4 inches apart, and pull - see how strong it is.
• Hold the fabric an inch or two away from the selvage, but still parallel to the selvage, and pull again - see how strong it is (although not quite as strong as the selvage).
• Do the same on the crosswise grain - many fabrics have quite a bit of stretch on the cross grain.
• Do the same on the bias - there will be significant stretch.

Place On Fold

If it is a "place on fold" line, then you must make sure that you fold the fabric so that the selvages are parallel to each other (in most cases, that means one on top of the other, with the fabric folded exactly in half lengthwise, similar to how it comes off of the bolt at the fabric store).

A side note about folding the fabric in half lengthwise: most of the time, the fabric is cut off of the bolt crookedly - sometimes a whole lot. And it's not necessarily the fault of the cutter - sometimes one half of the fabric has shifted somewhat on the fold.

Here's a photo showing some pre-washed fabric folded in half so that the ends of the selvages are aligned. Note the warped fold.

When I folded the fabric so that the fold and the selvages were parallel and there was no warp, the crooked cut was much more obvious. (I held the selvages up, and moved one against the other until the warp disappeared.)

Straight of Grain Line

Now it is time to talk about pattern pieces with a straight of grain line, and how to position those pieces on the fabric properly.

This photo shows the pattern laid onto the fabric, and one end of the grainline is pinned - the pin is just picking up a little bit of the fabric, because I'm going to want to swivel the paper a bit. The ruler is laid with one end at the edge of the fabric. The ruler is positioned next to the pin, which is at the 7" mark on the ruler.

One end of the grainline is stablized by that pin. Now move the ruler over to the other end of the grainline. Here you can see that the other end of the grainline is well past the 7" mark (yes, I did that deliberately, to make the process clear - usually my initial placement is somewhat more accurate!).

Keeping the ruler steady, swivel the paper pattern until the second end of the grainline is at the same mark on the ruler as the first end.

Put at pin on the second end of the grainline, and you have the stability that you need to be able to finish pinning the remainder of the pattern piece to the fabric. If you use weights instead of pins, I recommend that you still pin the first end of the grainline, so that it is easy to swivel the paper.

And that is how to position pattern pieces with a straight of grain line.

There are some valid reasons to shift grain. But you must be careful in doing so.

• Maybe you have a really cool striped fabric, and you want to make a chevron on the front of your blouse (so that the stripes come together in the middle to form several Vees). (See the article on matching stripes and checks and plaids.) If the fabric is sturdy enough, then there will likely be no issue. If it is a finer fabric, it might make sense to underline it with a light fusible woven interfacing, with the grain of the interfacing at 45 degrees to the grain of the fabric - the interfacing would provide the desired stability.
• Maybe you have just enough fabric if you cut the pieces on the crosswise grain instead of the lengthwise grain. This will work if the crosswise stretch is not too significant. But if there is a lot of crosswise stretch, you could end up unhappy with the result. I have done it for pants, and some were ok and some always felt just a bit funny! (Maybe some day I'll break down and buy sufficient fabric (big grin)!!)
• Question to ask: how big and heavy is the off-grain piece? The answer will suggest how much it will warp.

Conclusion

The grain of the fabric should correspond with the grainlines on the pattern. It is possible to make the pattern pieces off-grain deliberately, under certain circumstances.