pre-shrink Zippers and Lace

I have been sewing since I was 10 but on my own since high school. You'd think I'd know this, but in thinking about it...it never crossed my mind as I just did it all together Are zippers (like Coats and Clark) for clothes/sewing...do they shrink? They say they are 100% polyester and I know poly doesn't shrink enough to even notice if at all. But still....do they? I say I never thought about it as I'd buy stuff...fabric, lace, zipper...everything I needed for outfits and then I always knew I had to wash/pre-shrink the fabric, and would always just toss the zippers in with everything else. But now... I haven't been doing clothes for about 10 years and am working on a pilgrim dress for my GD...had the fabric and all, but forgot the zipper and just bought it today. Since I am not close to the fabric store, I bought zippers of other colors that I know I will be working with and just tossed them all in a nylon bag ans washed them. But do you need to pre-shrink zippers? Same with lace. I'd buy 10yards or whatever needed and put it in nylon bags and wash it with everything else. Today, I finally found some on sale and bought a bunch...said it was 100% polyester and I took it off the rolls, and tossed it in with the zippers and washed it all. But does lace shrink? This lace is about2 inches thick and eyelet style. Some fancy, some plain. But habit makes me pre-wash it, but does it really have to be? I guess I will always do it just out of habit and "better safe than sorry" but would like to know the necessity of it. I could have had that dress done today if I hadn't waited to pre-shrink the zipper but I don't want a ruined garment either!