I don't wash unless I think it will shrink a lot or bleed. But I do wash flannel.

I guess it really depends on how much you like to iron. I know that when I don't wash, I have to do a light press, but when I wash, I have to iron. And I hate to iron.

If the fabrics are flannels or batiks, washing is a must. Flannels because of shrinkage, and batiks because there may be left over dyes from the batiking process. Rule of thumb used to be that reds / purples had to be washed because of bleeding, but that isn't always the case. You can do a test piece, but I've also been told horror stories about a fabrics bleeding in a quilt even after the fabric was pre-washed.

Also, if you are doing a swap of some type, check and make sure whether fabrics are supposed to be washed or not so everyone's fabrics are the same.

I do not wash before and so far no problems.

light colors, no. bright colors, YES

Only wash shades of red.

I wash all of it but flannel gets hot water and hot dryer!!!

I am a firm believer in pre-washing. I have had some very expensive LQS fabric shrink more than 1/8 inch after washing. I prefer to control the outcome of my quilt project as much as possible. So I pre-wash for: color bleed, fabric shrinkage, etc. I also second the opinion about warehouses and most storerooms. Have you ever been in one? They are nasty.

I know you should...but I don't. To me it adds to the element of nubbie~ness that I want. I use color catchers always when washing quilts too.

I'm rather new to quilting. The first 2 I made I did not prewash the fabric. I really like the crispness of the fabric while I'm working with it. BUT, then this bedbug thing started and the quilt I'm working on now I order the fabric online from Hancock Fabric so I did prewash. It shrunk more than I though it would. I still had enough fabric but I wasn't expecting as much shrinkage. It was rather inexpensive fabric, not sure if this was a factor or not.

Just use Magic Sizing when you iron and your crispness will return. Or if you really want to control that bias stretch use starch.