Today I’m sharing some tricks I found helpful for sewing with thick sweatshirt material. My starting point is my usual method for sewing knit fabric (as opposed to woven fabric) on a regular sewing machine, so use these tips alongside the tips in the Coco sewing pattern instructions and/or our Learn to Sew Jersey Tops video workshop.
1) Beware shrinkage
Sweatshirt fabrics can shrink quite a bit. I discovered this the hard way! Embarrassing story – my red Coco sweatshirt was originally supposed to be a dress, but the second time I washed it, it became so indecently short I had to re-hem it as a top! So you may want to pre-wash your fabric twice before cutting it out, and also add some length to the hem and sleeves to be on the safe side. For the second (black) version, I lengthened the hemline by about 7cm (3in).
2) Allow extra fabric for folds
As well as lengthening the hem to allow for shrinkage, if the pattern your using isn’t designed specifically for thick sweatshirt fabric, it’s a good idea to increase the length on any area that involves a fold, since thicker fabric needs extra allowance to fold over itself. I found I needed to add about 7cm (3in) to the depth of the funnel neck piece on Coco, since the fold was so bulky. It’s also a good idea to create a deeper hem allowance so the thick hem doesn’t pop out or sit awkwardly.
3) Ease off on the presser foot pressure
Since sweatshirt fabric can be pretty thick, it helps to reduce the presser foot pressure on your sewing machine so you can get multiple layers under it without too much squidging. Your sewing machine manual will tell you where the presser foot pressure dial is on your model, if it's adjustable.
4) Adjust the stitch length
I also lengthened the stitch length slightly from my usual 2.2mm to 2.6mm, and lowered the thread tension slightly, again to avoid too much squidgeage (technical term) of the thick fabric under the stitches. (You can sew with straight stitch on the vertical seams and zigzag stitch on the horizontal seams as usual.)
5) Go easy on the iron
Not so much a must, just a time-saving tip ;) The good news is that I found I didn't need to use my iron much between stitching. Don’t tell me off! Finger pressing was enough to fold most of the seams down neatly enough before the next bit of stitching, and I just gave everything a good press at the end. Hooray!
Do you have tips of your own for sewing with sweatshirt knits? Do share!