Sunday, June 8, 2008

Guide: Trueing Up Grain and Preshrinking Fabric

Trueing Up Grains

Before preshrinking, it is important to
grain up the fabrics. You want to make sure that your cross grain is perpendicular to your lengthwise grain. If it isn't, you need to straighten it. You want to do this with dry fabric.

Fashion fabric: Pull a thread if you can, then cut along the line created to get a straight cut across the grain of the fabric.

If you've got a double woven fabric or a felted wool, such as a Melton wool, this is not going to be possible. In that case, try tearing it (see Q&A at end of post). And if that doesn't work, just start picking the yarns out until you can pull one out all the way across. What you want is a length of fabric that is cut along a thread line on both ends.

To true up your linings, first pull a thread, next cut on the pull line, then fray out a few yarns until you've got a nice clean edge. For underlinings/interlinings that are cotton or silk batiste, flannel, or broadcloth, tear the fabric. All those plain woven fabrics tear well.

Check each of your fabrics to make sure that the cross grainlines are perpendicular to your lengthwise grainlines.

Preshrinking Fabric

Here's the London Shrink method of preshrinking wool. (With permission and compliments of Lisa Laree at Sew Random [Red typing is mine])

  1. Run a bedsheet through the 'rinse only' cycle to dampen it.

  2. Carefully spread the sheet out, then lay your wool fabric flat (single layer) on it. Roll/fold the fabric and damp sheet together and let them rest overnight. After laying out your fabric, fold the sheet back over the top of your fabric (this may take more than one sheet for a piece of 60"-wide fabric long enough to make a full-length coat), then fold in quarters or thirds lengthwise, toward the middle. Fold again from the ends toward the center, until you've got a rectangle that resembles a packed parachute.

  3. Lay the fabric out flat to dry. Before pressing, you want to make sure that your cross grain is still perpendicular to your lengthwise grain. If it isn't, straighten it again. You want to do this with dry fabric.

  4. Steam press the fabric well, being careful not to stretch or distort the fabric while pressing (I have also read that you should allow each section to dry thoroughly after steam pressing before moving on to the next). If you have a grain board, or a knitting blocking board (photo below) that is marked off with grainlines, you'll want to press your fabric on it.



The wonderful thing about the knitting blocking board is that it's fabric marked with grid squares, which is placed over another sheet of fabric, then over a piece of needlepunched fleece, all so that it can handle the heat. I place mine directly on top of my cutting table.

If you're not a knitter, it's highly unlikely you'll have one of these very convenient tables. In that case, pad out a surface (not your dining table unless you don't care about the dining table finish.) Before I got my blocking board, I would pad the floor with towels (cotton towels, a double layer). Then cover it with a sheet or heavier cotton, that has a seam or line drawn on it, that you can check for right angles. To press, you want to be able to line up your wool with the selvage edge on one line and the cross grain edge on a line at a right angle to it.

Preshrinking Wool at the Cleaners

If you don't want to go through all that London Shrink method and pressing, then you might want to send it to the cleaners to have it steam pressed. Before you do that, true up your grain, making sure that your cross grain is perpendicular to your lengthwise grain, then fold your piece in half, lengthwise, and baste your ends and long edge together. This will assure that the cleaner doesn't skew it off grain while they're steam pressing it.

Ask though, when you take it in, that they leave the fold soft—do not press your fold line with a permanent crease.
I've done this frequently, and while they look at me a little askance, it's worked out well for me.

Preshrinking Your Linings, Interlinings and Underlinings

For dry cleanables such as silks, Kasha, Sunback, etc., you can have your cleaner steam press these too, after you've straightened the grain, or you may soak in water, line dry, then press them yourself. For the washable underlinings, especially those with a cotton content, throw them in the washing machine on hot, then dry on hot, then do again. If your underlining has a poly content in it, like one of mine does, go easy on the hot. You just want to make sure all the shrink is gone.

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I know all this sounds like a lot of fuss and bother—all this prep work before you even get to sewing. But if your fabric is off-grain, then all your sewing and careful tailoring work will be for naught. And, if your pattern doesn't fit you, you may end up with the most couture-finished garment in the world, but it won't look good.

We'll get this done, and then the fun part will begin.

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Q&A

Digs asked: What about felted flannel, Marji? My cashmere is made up of such short fibers, there's no way I can pick a full cross thread. Would it work if I simply cut the fabric one piece at a time, paying attention to the lengthwise grain and the nap?

Marji: Well, Digs—gasp!—try tearing it. I encountered the same issue with my purple felted wool. Then I got frustrated, and cut a snip 1" in from the end cut, and started tearing, and it tore beautifully!

Last night I was able, picking with a pin, to very carefully get a whole thread across my double-faced wool/cashmere: It broke in several places because the yarns are so soft. And a big thank you to Gorgeous Fabrics (Ann) who sent me a piece that was already trued, because it too had been torn. Try it!

7 comments:

Digs said...

What about felted flannel, Marji? My cashmere is made up such short fibers, there's no way I can pick a full cross thread. Would it work if I simply cut the fabric one piece at a time, paying attention to the lengthwise grain & the nap?

Marji said...

Well Digs, Gasp - try tearing it. I encountered the same issue with my purple felted wool. Then I got frustrated, and cut a snip 1" in from the end cut, and started tearing, and it tore beautifully!

I was able, last night, picking with a pin, to very carefully get a whole thread across my double faced wool/cashmere - it broke in several places because the yarns are so soft. And Big thank you's to Gorgeous Fabrics who sent me a piece that was already there, because it too had been torn.
Try it!

Nancy K said...

I got my yellow double faced wool today and it is already straightened! I pulled a thread across on both ends and hallelujah, it's straight. It is really lovely, and I think that I am going to take it to the cleaners for steaming.

Digs said...

Whaddya know, it WORKED!!!! I ripped the ends of both my flannels (BIG GULP!) - and afterwards, the wool/cash blend yielded a beautiful long single thread all the way across, selvage to selvage. Perfect! You're brilliant.

Rose said...

I have some rain repellant fabric for a raincoat. The fabric is 100% cotton that is similar to medium weight denim. I believe it needs to be prewashed but I wonder about the rain repellant backing. Does anyone have any experience working with this kind of fabric and how did you prepare the fabric?

Ms. Fine Fabrics said...

I remember as a child the ritual of straightening the grain on all fabrics. My sister and I would both repeatedly pull from opposite corners along the bias. I don't think we ever checked whether it needed it or not, and I doubt if we really checked - pulled a thread - after we were done, but we certainly had a lot of fun playing tug of war. I hadn't thought of that in a long time.

Dawn said...

I just recieved my fabric in the mail; a flannel coating and a melton wool. I put 5" squares in the washer and dryer and it came out beautifully w/o shrinking much at all. Is there a problem with putting the wool in the washer/dryer? The melton seemed to not change at all and the flannel got a little beefier but basically feels the same. Do I dare throw them in the washer and then dry them? I would put them in separately.