patterns for stretch or knit fabrics
What are the most basic guidelines to follow when fitting and altering a pattern that calls for a stretch knit. I know to use the stretch guide on the back of the envelope, but what else? I guess tissue fitting is out of picture when you are going to make a stretch knit garment?
Most patterns designed for stretch knits are not very complicated fitting-wise. Probably the most important caution is to err toward the larger size, as you can always take it in, but are limited in how much you can let it out!
Although tissue-fitting won't help much with knits, it's not a bad idea to hold the fabric up to your body and check out the effect of stretch and fit. Sometimes, a knit will look sloppy if it's too loose but look unflattering if it's stretched too tightly. If you pin-mark side seams on the uncut knit fabric while holding it up to your body, you'll get an idea of the amount of ease that particular fabric will need in the pattern.
So if you err toward the larger size and it turns out it's going to be too big after all, do you have to re-cut the fabric or do you just sew deeper seams?
If the adjustment is under 1/2" or so per seam, I sew deeper seams and trim off the excess just outside the original seam line so that I get a pre-finished seam allowance.
If it's the first time using a particular pattern or knit, I usually stitch the original seams in a very long, loose basting stitch in case it's way off and I need to pull it out. If it's correct, I just leave it in and stitch over it with a narrow, short zigzag or a stretch stitch for the permanent seam.
An easy way to pin-fit knits is to try on the garment inside-out, so that the pins become the seam line to guide your stitching.
I'm not a pro with knits, I generally use wovens. My pattern drafting books advise that knits are drafted with little ease to negative ease. This means that the width of the finished garment is the same as your measurements or smaller than your measurements. I have found from measuring commercial patterns that the ones calling for knits that stretch from 4" to 6" run 1 size smaller. I made Vogue 2064 in a woven fabric 1 size larger than my size and it fit great. I did have to cut the lower sleeve larger to get my big mitts through. So, with knit patterns, in my experience, measure it. Stretch slightly while stitching, but be conservative. Too much stretch will cause the seam to ripple. Test a scrap first to get the best stitch length.
I've never stretched knits while sewing. Well, I did when I first started sewing for about 5 minutes and the distortion was so bad with causing uneven width in the seam allowance that I did all I could not to stretch it from then on. but I do use a stretch stitch or narrow zig zag. How do you stretch it while sewing and still get the accurate seam allowance? Do you like rotary cutter or scissors when you cut it out. I read somewhere to use pattern weights, but I found the fabric shrunk back under the pattern tissue after it was cut and probably wouldn't have happened had I pinned instead.
Edited 7/23/2007 12:42 am ET by surya
Well, my rotary mat is only 18x24 and I don't like to move the fabric around in the middle of cutting so I pin and use scissors for garments. I use the mat for smaller stuff like binding strips.
This is kind of difficult, because I don't have the wavy seams or the stretched out neck that I hear other people having, and I don't know how to describe my methods. I always give a quick run on the machines through a scrap leftover from cutting before I put the garment to the needle, to determine best stitch lengths. I haven't really thought about it but I pull the fabric both in front of the needle and in the back, so the fabric is stretched but it feeds evenly under the foot so the stitching is even. I use a longer stitch length 3-3.5mm and I steam press every seam. The steam pulls the fabric back into shape. On loose fitting things or items I've made many times so I KNOW the fit is right, I'll serge only, but mostly I save the serging for seam finishing. I like to have that seam allowance safety net. I do use a straight stitch, and if the seam allowance shrinks to 1/2" when I stretch, then I stick to 1/2" throughout. I don't really stretch enough to distort the seam allowance very much.
I have Ann Person's books and she adamently states that you have to stretch slightly or the stitches will break when you move. Especially the neckline. I've read some posts here that some ladies have a ripple around the neck. I don't get that either, so I can only tell you what my personal experience is. Ann's T-shirt pattern doesn't fit around the head so I've always measured my kids heads and then stretched out the knit that I'm using, I figure out the percentage of stretch and divide the kids head measurement by that amount and that's what length the neck band is. Then I increase by 25% (seam allowance and a little extra to make the band lie flat) and use a flexible ruler to draw the neckline on the T and cut it out. So, I guess I redraft the neckline on every T I make to match the fabric. Does this make sense? I just couldn't throw out a perfectly good T pattern because my kids heads didn't fit through a little hole. My common sense just said make the hole bigger.
Edited 7/23/2007 11:47 am ET by CostumerVal
Thanks for such a detailed and carefully written reply. I think I have the same size cutting mat as you, so I like to use scissors and pins a lot too. It's on my list to get one of those gigantic mats someday though. I'm going to do some experimenting with the stretching on scraps and see how I like it.
Yea, the big one is on my Christmas list, if I could lay it on the bed and store it underneath then I wouldn't have to wash dishes and clean the table before I cut fabric. LOL
Reread some of my Stretch and Sew book while sitting at swimming lessons. Should clarify that Ann uses a 2:3 ratio for rib knit neck trim with 50-75% stretch, and a 3:4 ratio for self fabric band with 25-50% stretch. I use self fabric on the kids night shirts so I just cut the neck 25% larger than the trim. She cuts the neck and then measures the trim. I did this once on my then 3yr old and the neck was to big. Ever since then I measure the trim to the head and cut the neckline to the trim. Good luck, knits are very forgiving and very fun. Val
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