Has your LA quilted on batik quilts before? Batiks as you know are often more tightly woven than regular quilting cotton.
I am in Canada and have am currently using Fabric Land (our equivalent of Joann's) wide backing on a quilt (not batik) with no issues.
Don't tell the quilt police, but I did not wash the backing. The top is a Jelly Roll Race. I do not wash precuts before using them, so neither the top not back have been washed. No skipped stitches, but it may be beginners luck.
Batting: Warm and Natural.
Thread: Connecting Threads cotton