Working With Knitted Fabrics: Using Interfacing With Knits

As much as I detest working with interfacing, sometimes it's inevitable. Sometimes you need to stiffen up your fabric, or just add a little more stability. Knits, like other fabrics, can often benefit from a little more stability, depending on the project, of course. Unlike other fabrics, however, knits require a very specific interfacing. Woven and nonwoven fusible interfacings are simply too rigid and usually cause the knit fabric to bubble or pucker after fusing. And after fusing is too late to fix it.

Prevent this problem by choosing your interfacing with care. Tricot knit interfacing, available at most fabric stores, is lightweight and stretchy. This makes it less noticeable when fused to knit fabrics. It also won't damage knit fabrics the way other fusible interfacings can. So do yourself a favor and choose the right interfacing based on the fabric you're using. Don't just grab whatever happens to be on the shelf.

Working With Knit Fabrics: Supporting Your Fabrics

I recently returned back to my home sewing center with a friend. We were carrying several hundred dollars of new and very pretty material. The phone was ringing, so my friend gathered up the material, assured me she would put it all away, and ushered me toward the phone.

Well, it was a lengthy phone call. My friend wandered out of my storage room before I managed to get off the phone. When I did finally hang up, we visited for a while and she left to collect her kids from school. I went up to my office to answer a few e-mails. It was the next morning before I went into my storage room to gather up some fabric for my next project. And I could have slapped my friend.

The fabrics were put away all right. But they were all hanging. All of them. Now, it's perfectly find to hang fabrics. I do it all the time. But there are some fabrics that you must not hang. Ever. But there was a bolt of beautiful rose fabric hanging over one of the tower rods. The problem? The beautiful rose fabric was a knit. That's why I have shelves.

Knits stretch. They're designed for it. It's what allows knitted fabrics to conform to the body. They're great for making form-fitting garments, but this stretch has a downside. Knitted fabrics have a tendency to grow and stretch when left hanging. So the overnight hang on the towel rod? Well, I can't use that bolt of fabric, at least not for its intended purpose.

It would have been fine if the fabric could regain its original shape. But the "growth" of knitted fabrics can cause inaccurate cuts, distorted pattern pieces, and wavy seams. And it's not reversible. And it's not just hanging over night that causes this problem. You can ruin a delicate knit simply by allowing the fabric to hang over the table edge as you cut out a pattern piece.

To avoid this particular problem, always ensure your knitted fabrics are supported. When you're cutting fabrics, pile the excess fabric on the edge of the table instead of letting it hang. When stitching a seam, support all of the fabric on your lap or on the table rather than allowing it to droop off the sewing surface. And when storing knits, fold or roll them carefully and place them on a shelf. Don't hang them. You don't want misshapen fabric when you sit down to sew.

Working With Knit Fabrics: Needles and Pins

Yep, I'm still working with knits over here. Turns out there was more to do than I'd thought. And while sewing yesterday, I remembered a tip I gave a couple weeks ago. The one about not using pins to hold the pattern onto the fabric for fear of damaging your knits. Well, I think maybe I should go a little further with that particular tip. Why? Because pins aren't the only thing that can cause knitted fabrics to run or tear.

When you run a piece of fabric through your sewing machine, you use a sewing needle. This needle can and probably will pierce the fabric in just the wrong place. This will cause your seam to split or pop and the fabric might even be ruined. So how do you avoid this and still use knitted fabrics in your projects?

To avoid skipped stitches and popped seams, switch to a ballpoint needle. You can get these at any sewing supply shop and most craft stores. They're often labelled as being "for knits" so they're not hard to find. Ballpoint needles have a rounded tip and are designed to slip between the knit fabric loops instead of piercing the fabric itself. You should also consider using a polyester thread when working with knits. Polyester thread is both stronger and more flexible than cotton, so it will stretch with the fabric instead of snapping as cotton threads might.

So before you start working with knits take the time to get the right supplies. It wills save you the grief and aggravation of a ruined project or two.

Working With Knit Fabrics: Selecing a Fabric Based on Stretch Factor

Knit fabrics are tricky because different knits stretch differently and the ability to recover after stretching is not consistent between fabrics. Commercial patterns that recommend knit fabrics are designed for different degrees of stretch, so check the pattern envelope for the appropirate stretch gauge before selecting a fabric.

It's also important to know what kind of stretch the fabric you're selecting might have. There are basically two kinds of stretch. The fabric might only stretch horizontally (called two-way stretch) or it might stretch both horizontally and vertically (called four-way stretch). This can be determined simply by picking up the fabric and stretching it both ways. These are not usually interchangeable. For example, if I'm making a fitted gown out of a knit fabric (which I just did yesterday), then you probably want a fabric that has only horizontal stretch. After all, you may not want the gown to stretch downward. Horiztonal stretch will allow the gown to cling to the body without hanging ... oddly after a few washes. But a four-way stretch might be better for a slip cover or tight leggings. It all depends on the final product, so test before you buy.

Also pay attention to the fabric content. Knit fabrics made of synthetic fibres tend to have better recovery than natural fibres, so if you're hoping to make something that will keep its shape after many wears, look for a fabric with at least some synthetic content. A gown made entirely of wool, for example, will eventually lose its shape.

The bottom line is you absolutely must know what you're making with a knit fabric before you grab it off the shelf. Stretch factor and fabric content are very important when you decide to work with knit fabrics, so consider these things before you go out fabric shopping.