I've channel quilted every 2" the full length of king size tumbling blocks quilt. My question is: should I still cross quilt to be sure batting will stay put in those long 2"-apart-channels?
Warm & White batting says can quilt up to 10" apart. Customer service lady at Warm Co. assured me on the phone today that the 2" channels would be plenty, but I'm still wondering if I should trust that the batting in those channels will be sufficiently stitched down to avoid later laundering rigors.
I'm more inclined to trust the experienced input of my quilting friends on this website!
Thanks in advance for any insights you can offer.

i think you would need to at least quilt across your channels every 10" if not more...every 10" means all directions, so, i would worry about the batting migrating into lumps within those channels if they are not stitched across at least here and there.

Okay, that confirms what my instincts said, even though this is the first large item I've quilted. Thanks so much!

Even if it is stable at 2" - to me it looks unfinished. Quilting in the world of MQ needs to go up/down and across.

I would. It may take a bit of time, but it would be worth it.

Later on you would always say "Darn, sure wished I had gone in the other direction, too".