What is the Grain?
As I mentioned above, the grain is the term used to describe the direction in which the fabric is woven in relation to your pattern pieces. There's three types of grain - lengthwise
and bias -
as illustrated in the image above.
Fabric is manufactured by criss-crossing threads over one another on huge round bolts. The warp threads are long ones that run from cut end to cut end down the bolt of fabric (lengthwise
) and the weft threads weave in from side to side (crosswise
). For distribution purposes, the finished fabric is then folded in half, lengthwise, and rolled onto those rectangular cardboard “bolts” you see lining the aisles of fabric retailers.
When you buy fabric off the bolt (in store or online), they unwind however much you want, then either rip it or cut it off with scissors. The fabric can be on that bolt of fabric for a long time and it can crinkle and crease in odd spots. Along either side (perpendicular to the cut edge) are the factory-finished edges called the selvage (or selvedge depending on where you are in the world). Selvedges are formed when the weft threads change direction during the weaving process. They have a different texture, do not fray and often have a manufacturing stamp on them. They should be trimmed off when you cut out your final pattern or pieces.
Why Is Grain Important?
The reason finding the grainline is so important is simple: fit. You want your clothes and projects to drape and fit properly without twisting in odd places.
The bias grain (your fabric is cut at a 45° angle across the threads) also allows woven fabric to stretch and curve. If you cut patchwork pieces too close to the bias, your quilt will have bubbles and puckers where the fabric pieces have stretched and moved as you've sewn them together but a skirt panel cut on the bias gives a beautiful flowing drape. Take it slow and steady when working with anything cut on the bias.
How to Find the Grain
When a fabric is "on-grain," the lengthwise and crosswise threads are at an exact right angle to each other. Fabrics patterns like gingham always follow the grain because the pattern is made using the warp and weft threads. Finding the correct grain can be harder with printed fabrics as the base fabric might not have been square during the printing process.
I use a clear plastic ruler and a rotary cutter to cut almost all of my fabrics but this process would work equally well with a pair of scissors.
Before You Sew:
- Pre-wash all woven fabrics. I find it brings on any warping and shrinkage first up rather than the first wash of my finished project. Pre-washing is just dunking up and down in a bucket of warm soapy water - I wrote about my process here.
- Iron the fabric flat. It really depends on the fabric but I try and line up selvedges as closely together as possible while also keeping a flat fold. If your fabric is warped (or off-grain) then you'll notice little ripples or puckering folds over near the main fold. See image below as an example. I move the fabric around and attempt to find middle ground of a nice straight lengthwise fold and 'not too out of alignment' selvedges.
- Clear the decks and work on a large flat surface.
1. I use a clear ruler and match one of the marked lines along the line of the fold.
2. Trim the cut edge so it's straight.
3. Once you've got one straight edge, it's easy to work out the others. Align your ruler along the edge you just cut and trim off the selvedges.
4. Repeat the process to cut across the top and other side to complete a rectangular piece.
Ashley over at Make It, Love It has a great tutorial using scissors. Read More...
Another option to find the crosswise grain is to snip and rip a small section from the cut edge or pull an individual thread abt 1" / 25mm from the cut edge.
What to do about a wonky grainline
I know, insert eye roll here, but it depends on how much it's out. It it's only just a little wonky then a good press with some shots of steam and you should be able to get things back straight on grain again.
More drastic wobbles might require more drastic measures such as a good tug across the diagonals to get those misbehaving threads back in alignment or even wetting the fabric and re-pressing while still damp.
The process of wetting fabric and pulling it to make it square is called 'blocking' (a similar term is used in knitting projects). The Craftsy blog has a good tutorial - http://www.craftsy.com/blog/2014/01/fabric-blocking/