I would so there's no shrinkage surprises, and also to get the sizing out. You could wash it, and then air dry it so it's not quite so wrinkled.

I agree with ideefixe and also, as a bonus, if there is any dye or any chemicals in it, you will have eliminated smell and out-gassing.

Donna, I've made WTs for all four of our homes and one rental through 29 years of marriage. I have never prewashed the fabric. The sizing (basically starch)gives the fabric body and helps it lay better. If you're worried about out-gassing let it air outside before you do any cutting.
I also have over a decade experience selling fabrics and being the in-store expert on make window treatments. I never had a complaint about not washing the fabric from a customer. All Cotton fabric shinks, but at the most it's just 3 percent in length. If you are still worried, allow that much extra length in your hem. Just incase.

I agree with justgotabme. Home dec fabrics usually have finish and/or stain resistance treatments that are destroyed when you wash the fabric. Ideally the fabric should be dry cleaned to retain the finish, but the label will tell you how the fabric should be cleaned.

If I am using fabric in the kitchen or bath where I know it will get dirty, I buy a fabric that can be pre-washed, knowing that I will lose the finish. For drapes and shades, I do not pre-wash and plan on having them dry cleaned.
Diane

The only fabric I have ever pre-washed was some Toile for my daughters duvet. I bought it on eBay and when it came, it was obviously from a smokers home. :(

Thanks all. I want to say that I'm not making curtains for anyone, I do good making them for me...lol. The out-gassing isn't what I really wondered about. It is more what the fabric is going to look like once it has been washed and dried since it already had the stiffness (body), and absolutely no wrinkles before washing. From experience, I know that any heavy cotton that has been pre-washed and then pressed isn't going to make it look or lay the same as it did coming off the bolt, but then that is what some of you are telling me:) Just wondering how professionals did it. I mean, if you're a professional sewer making curtains for someone, do you ask them first if they want it prewashed? Not everyone is going to want to pay to have them dry cleaned. Then maybe again, I guess those who don't want to pay to have it dry-cleaned aren't going to go with the more expensive fabric. They'll probably buy store bought curtains instead. Again, I was just curious as to how professionals do it.

I bought some remnants from a professional and she didn't prewash her cotton. I did as I was going to make heavy duty quilts out of the scraps, and I could really tell they difference afterward. They faded quite a bit even in cold water without being in the dryer. Unless you will be washing them sometime, I wouldn't prewash. However, if you are going to wash them EVER, do prewash because there is some shrinkage and they won't fit the same after washing. If you do wash, there is spray sizing you can apply to it to give it the body and stiffness it had before. It still won't be like new, stiffer fabric though.

Decorator fabric does not need to be washed first. It has a nice finish that washing would eliminate. And when your drapes are made, you maintain them by vacuuming. Drapes should very seldom need drycleaning.

If you're making kitchen curtains or baby room curtains, you might buy a washable fabric so them can be laundered as needed.

Red

I've had a lot of professional work done, and I also do my own sewing. Fabric has never been pre-washed. Also, unless the fabrics are handled a lot (or in a greasy, smokey kitchen), they shouldn't get dirty to the point of needing a wash. If animal hairs get on drapery, for example, use the vacuum attachment. A good shake-out will help get rid of an accumulation of dust.

Ok, so here's my recent dilema. I made valances for my Mom's kitchen two months ago. I didn't prewash and they came out great. A couple days ago she fell asleep while boiling a hot dog (another problem to deal with) and woke from the alarms going off. Smoke from this burnt weenie was everywhere. Since then (yes she will not cook and sit anymore)she has wiped down the kitchen cabinets and walls, aired out the room as much as possible but it still smells. We're pretty sure it's in the valances. Do I wash in cold water and air dry, or do they have to go to the cleaners, or could I hang them outside to air out? I'm not looking forward do ironing these after washing.

I've never used decorator fabric for my kitchen for that reason. I use 45" wide cotton that I can take down and throw in the washer and dryer. I've made them twice in the past. I could care less about them being lined (in the kitchen), as I have miniblinds up. Actually right now I have 3 pairs up that I bought at KMart. Only thing about them is they're not wide enough for a 36" window, and that's using both panels. The top valance isn't as wide as I would like it either. I mean, they're ok, but you don't get the fullness of gathers on the rod if they had made them wider. Now the one pair on my back door in the kitchen looks great since the window on the door is smaller, so the curtains have more gathers.

I use decorator fabric purchased from mill end stores, if that's the 100% cotton fabric you have...then do nothing to it! Like another poster said. It's got treatments on it to repell water, stiffener and "no" wrinkles.

I'll tell ya a story...I made warm window coverings with a matching duvet and shams. Then I stenciled the pattern from the fabric as a border in the room....hand painting it onto the walls. House sold in 3 weeks.....was told the new owner liked all the decorator touches....lol

About 3 years later the couple contacted me, said she'd taken the duvet to the dry cleaners and the colors had run. The cleaners claimed the fabric was hand painted and to contact the artist......"WHAT?" It was ruined and the fabric was no longer made.

GOOD! I just got a lot of fabric and could not imagine washing and ironing them before attempting to sew (it's been years since I've done it). My instinct was to not wash, and just dry clean if I ever need to.

NatesGramma, have you tried Frebreeze on the valances yet?

Thank you so much for your help. Now I feel better about getting started.

I wash it first only if I plan on washing it afterwards...like the valance in the kitchen. Also, you may need to trim off the selvages as they may shrink more than the rest of the fabric.

If I don't plan on washing them...like my faux hobbled roman shade valances that are mounted to a board...then I don't wash the fabric as it destroys the finish. Those valances get vacuumed to get the dust out.

Thank You Annie