I mix just about everything and anything that's cotton or mostly cotton, and have never had issues. The quilt police never come to my house, so I haven't worried about it. If I like it, I use it! I watched a youtube video just a few days ago by a gal who uses wool, silk, cottons, any natural fibers of all weights to make her quilts. They were beautiful and she had some tips for working with the different wights of fabrics. I can't seem to find it or I would post a link. If I find it I will try to remember and come back to post it.

I have never had a problem mixing batiks and prints. Heck, sometimes I get wild and even throw in some solids and hand-dyes too! Never had a problem!

Never given it a thought. My current project is Kona Snow, Batiks, Kaffe and a few random jelly roll strips.

To be honest, I don't like to mix them, not because of any problem but when I use batiks I only want batiks. (if this makes any sense!)

I prefer the look of using them separately. There definitely is a sewing difference on my machine.

Make sure you wash the Batiks at least before using. They will bleed and shrink, I'd wash them all but especially the Batiks.

Makes so much sense. They have a special look that can be lost when mixed sometimes.

I wash everything first but have mixed batiks and cottons many times with no problems

I'm a big believer in prewashing everything, especially batiks. But like others here, I mix and match them all the time with regular printed fabrics and solids. My last project was a grandmother's fan and has batiks mixed along with the other fan blades, current project is using up my old Y2K squares and there were a number of batiks in those.

I've seen discussions with people who have had problems with stitch tensions and such, never have myself but then I change my needles all the time and typically use a 10 for piecing.

Edit: Here's a picture of one of my turkey fan blocks -- is funny that there is indeed a batik in it.