Short answer to this question is yes. Longer answer is maybe. I know pre-washing is kind of suck. You go to the store, get some lovely fabric and want to go home with it and make something with it right now! But trust me, while you can get away with NOT pre-washing for some things, for other stuff you’ll kick yourself if you don’t.
Why pre-wash? Isn’t new fabric clean already?
Yep, new fabric is generally nice and clean – unless it’s a factory second or has been fondled by grubby hands in the store. Pre-washing isn’t about cleaning your new fabric, it’s about making sure your fabric is ready to use.
New fabric may have a number of treatments applied to keep it nice and crisp while it’s processed, these need to be removed. You might notice with cotton especially, the new stuff feels slightly stiff. You need to wash that treatment out before you can sew with it.
The other reason for pre-washing is shrinkage. Most fabrics will shrink a little bit when they’re first washed – you don’t want that first washing to be AFTER you’ve slaved over a shirt or pants because your perfectly fitting clothes will get a bit smaller.
Finally, any dyed fabric still has surface dye – this is the stuff that doesn’t rinse all the way out. It’s much better to get rid of this first so that your new whatever doesn’t disappoint you by dying all your underwear purple.
Okay, so when do I have to pre-wash?
If you’re making anything that will need washing after it’s made, pre-wash your fabric. That includes clothes, childrens’ toys, soft furnishings, quilts – basically anything that at any point you’ll want to throw in the machine or hand wash, you’ll save yourself a lot of frustration by pre-washing your fabric. Even if it’s something that will only be surface washed with a damp cloth – get rid of the surface dye before you make it up.
And when can I get away with not pre-washing?
Softies for adults, fabric you’re going to embroider and frame. Anything that’s not likely to get grubby and need cleaning, basically. I tend not to pre-wash when doing applique for framing or making toys for adults. For applique on clothes – yeah pre-wash that shit.
Can I pre-wash anyway?
Can and frankly, probably should. I’m just lazy. If in doubt, wash it, basically.
So you have the why, you have the when. The how is pretty easy. For fat quarters I tend to hand wash in a bucket because they fray so much in the machine. For bigger pieces, I just toss them in the machine. Usually with the towels because it’s a waste of a cycle otherwise (save water!) and because if there’s any loose dye flying around the towels catch it (makes for interesting towels sometimes – don’t do this if you’ve thoughtfully matched your towels to your decor). Washing instructions for your fabric are on the tag on the end of the bolt you bought it from, if there’s anything more complicated than machine wash, might be worth taking notes. Remember that those instructions also apply to your finished garment or item.
Am I helpful yet?