Friday, March 26, 2010

Some thoughts on choosing knit fabrics

I get asked about knit fabrics a lot. I love working with knits, but they come with their own special challenges. Here are some thoughts that I have about choosing which knits you want to sew with, especially for t-shirts, knit dresses, and the camisole/panties sets.

When you purchase your fabric, buy at least 1/4 yard extra for shrinkage and practicing stretch stitches. Pre-wash your fabric as you intend to wash the finished garment. I wash and dry my fabric up to three times before cutting and sewing, just to be sure it won't shrink after I sew it!

Some thoughts on fabric:
There are many kinds of knit fabric on the market, including variances in content (cotton, poly, bamboo, hemp, wool, silk, lycra, etc.) and variances in how the fabric is made, which affects its stretch.

Knit patterns all have a stretch requirement. Fitted garments often require about 40% stretch. There is a line on the back of the pattern marked with a black box and white arrow. You can hold the fabric to the pattern, stretch it, and if it goes to the end of the black box/white arrow, it is stretchy enough to use. Don’t try to stretch the selvedge. Use the middle of the fabric and stretch away from (perpendicular to) the selvedge.

Interlock knits are knit in a special way so the fabric is double-sided, without right and wrong sides. It does not roll, is very easy to work with and I highly recommend it for your first t-shirt! It usually has a 30-40% stretch.

Jersey knits, also called single knits, are very common, fairly thin, and have a tendency to roll. They have an obvious right side and wrong side, just like hand knit items. The amount they roll can be a big challenge when you are cutting out and sewing the pattern. But the fabric has a lovely drape, with 25%-50% stretch. Those who are up for a challenge or who have a serger will find jersey knits very rewarding to sew.

Double knits aren’t just made from that awful polyester from the 70s. Now commonly found in 100% cotton or cotton blends, it is similar to interlock knits in that it doesn’t have a right or wrong side and does not roll. It is usually heavier weight than interlock and has minimal stretch. I wouldn’t recommend it for a t-shirt.

Rib knits are generally used for necklines and cuffs because they have 100% stretch – meaning 4” of ribbing will stretch to 8” and then rebound back to 4” when you let go of it. There are some rib knits that are very fine and delicate, making them good for a t-shirt. They do not have a right or wrong side and do not roll.

When you check the stretch of a fabric, don’t stretch the selvedge edge, but reach down a few inches and measure there. The selvedge will not stretch as much as the rest of the fabric. Stretch parallel to the selvedge and also perpendicular to the selvedge. One direction will stretch more than the other.

Bolt has a lot of very lovely knits. If you choose a stripe or a print, you might be surprised how easy it is to work with! Be sure to note the direction of the stripes! Imagine the selvedge edge running down the center of your shirt from neck to hem and make sure the stripes go the “right” direction for you!

1 comment:

Steph said...

Very helpful! Thanks!