I've been reading the thread on washing fabrics.... but my "problem" is that I have some fabric that has been washed. I probably heard from my first instructor to wash fabric first. But now there are many of you who do not wash your fabric before using it, and I think I like that plan, too!
Soooooo... can I mix my fabrics? My stash is really more of a "stashlet" compared to many of you... but I do have some already-washed-fabric.
HELP???

I'm a fly by the seat of my pants kind of quilter. I would just go for it and if you don't like it don't do that again.
I don't usually prewash.

It won't matter, I mix washed and pre-washed all the time, because I prewash dark blues and reds that are more at risk for running, and usually leave the rest unwashed. I like the wrinkly look that happens when thread/batting/fabric shrink a bit, and unpredictably. HOWEVER, if you are making a project and you don't want that effect, make sure you prewash everything.

I'm not normally a pre washer but since I've participated in a Row Robin I had to wash the fabrics I used. Now I have a lot of washed and unwashed fabrics. I've mixed the two with no problems so far.

I buy from the thrift shops and always wash those fabric's, you never know what might be in them. The store bought fabric I never worry about. So I mix mine and haven't had any problems yet.

The larger the pieces of fabric, the more important it is to not mix...if a fabric will shrink, the shrinkage will be more noticable in large pieces of fabric such as backing and borders...but for smaller pieces of fabric as in scrap quilts the shrinkage won't matter, so blending washed and un-washed is less critical.