The Power of Steam

There's an idea floating around the internet that you can prepare sweater knit fabric for cutting and sewing by first starching and ironing the fabric. I'm pretty sure this would change the hand and drape of the most sweater knits in some way, and I'm here to encourage you to never ever iron your sweater knits.

You may have noticed that I always use the word "steam" and never "press" throughout any blog posts on sewing with sweater knits. Simple steam does wonders for your natural fiber sweater as you construct it, but please never press or apply the weight of the iron to any sweater knit. And never let a hot iron directly touch synthetic sweater knit. 

Fiber Content of Sweater Knits

Always check the fiber content of your sweater knit fabric. My preference is for 100% natural fiber, but do look for a fabric that’s at least 55% cotton or 55% wool (the more natural fiber, the better). Though they may be  harder to find, linen and silk are great natural sweater knits too. Here’s the reason: You’ll use a considerable amount of steam in the construction of your sweater, and knits that are primarily synthetic fiber don’t hold up well under lots of steam. They lose shape and recovery and will sometimes melt if a hot iron touches them!

How to Steam Your Sweater Knits

Hold your iron a half inch above your fabric and allow the steam to do most of the work. The half-inch rule applies to natural fiber fabrics only. If you’re using a fabric with a high synthetic content, hold your iron about 2 inches above your fabric when applying steam. Let the fabric dry before moving on to the next piece. And never iron. That is, don't allow the iron to rest on a sweater knit fabric. Do not push the iron back and forth on the fabric. Do not press. Do not allow the iron to rest on the sweater knit. 

Whew! That’s a lot of don’ts! But there’s the exception, and it’s for natural fiber fabrics only. Keep reading.

Pressing When Using Fusibles

As I mention above, the only time you need to press is when using a fusible stabilizer. Again, this application is about the only time I'll actually press any area of a sweater knit. Pressing is necessary when using a fusible stabilizer, for example when stabilizing cardigan sweaters, or stabilizing shoulder seams, or hems. By pressing only the sewing line and seam or hem allowance, the iron won't spoil the beauty of the natural fabric. Remember this is pressing, not ironing. That is, I don't use a back and forth motion with the iron. It's press, hold (for the required number of seconds on the fusible product label), lift, and move to the next section. Always test on a scrap first. Again, this method is suggested for natural fabrics only! You'll need to sew in transparent elastic or another stabilizer if working with synthetics and many synthetic blends.

Using Steam with Spray Starch 

Is your fabric particularly stretchy and unstable? Is it making you nervous? Spray it liberally with spray starch and then steam it well (following the directions in the How to Steam Your Sweater Knits section above). Allow the fabric to dry before cutting. The fabric will be a little stiff as you work, but that's ok. The starch comes out in the wash. Be sure you test this method on a scrap first! 

Finishing Your Sweater with Steam 

There’s nothing like a good steaming to improve the look of your finished sweater. In fact, I don’t consider any sweater finished until it’s steamed. As you worked, your sweater was stretched out of shape to a certain extent. A good steaming will help the fabric recover. If you don’t have a large work area, steam one small section at a time and allow the area to dry before moving on to the next section. Just as you steamed before, allow the steam to penetrate the fabric. Use your free hand to shape the sweater into place. 

Steam is your friend and will help you create a well-executed, self-sewn sweater. 

If you're interested in more tips and my step-by-step instructions for cutting and sewing a sweater that fits you perfectly, please sign up for my How to Cut and Sew a Sweater course may be just right for you.

O!