Shrinking Shot Cottons

So after my girl Elise posted about some bleeding and shrinking issues with her shot cottons, I freaked just a little bit. My Mod Blocks quilt was made with shot cottons and I hadn't washed it yet (judge away). And it had black in it! Gah....
Mod Blocks
Annnnnnd.....I was starting another quilt for Modern Quilts Unlimited, again, with Kaffe Fassett shot cottons. But I had a royally horrible time with the quilting, so I needed to wash the quilt before sending it off to get rid of those pesky holes (from some quilting I ripped out). Shrinkage I could deal with, but bleeding? Oh no. That I could not deal with...
Well, luckily I didn't have to. It shrank, but did not bleed. Phew. However, I thought the shrinkage was worth reporting because it was significant.
This quilt started at 60.5'' x 72.5'' and ended up at 55'' x 66.5''. Yikes. That's a shrinkage of 9% across the width and 8% across the length. Most quilting cottons shrink around 3-5%.
The new quilt crinkled quite a bit, but it was quilted more loosely. It has a beautiful texture now.
The Mod Blocks quilt crinkled just barely.
It also shrank less - approximately 7.7% shrinkage in width and 6% shrinkage in length. It started at 78" x 90" and ended up at 72" x 85". I'm not quite sure why it seemed to shrink less. I used the same batting (Pellon Nature's Touch) in both of them.
This makes me worried about mixing the shot cottons and quilting cottons without prewashing. I thought back to one project where I did mix them: this pillow has both Kaffe Fassett shot cottons, Kaffe Fassett wovens, and regular quilting cottons.
It has been washed and pressed and still looks really nice. No problems with persistent wrinkles, like others have mentioned. I also didn't notice any visible issues/stress from the differences in shrinking percentages. In fact, after pressing, it doesn't even look as though it has been washed at all! This might be because a pillow is a small project, so I have no insight as to what would happen in a larger quilt.
All in all, if you would be disappointed by this amount of shrinkage, or if you are mixing your shot cottons in with other fabrics, you might consider prewashing. Generally, I'll continue to use them heartily, and will only prewash if I intend on mixing them. I do love using shot cottons - they are marvelously soft!!
StashingAmy Garro