I will second almost everything that Feline Fanatic said, except I DO know of a couple of longarmers who have struggled with certain batiks (thwock thwock thwock). Interestingly, one specific longarming acquaintance of mine refused to give up. She was very experienced but had awful tension issues with the batiks, and she could not get them resolved despite all of her skills. So she did a bunch of online research and experimented until she found a solution that worked - she sprayed silicone fabric spray on the quilt top.