I almost always use invisible thread to SID on my tops. I use cotton thread on the bottom. I do not have a problem as long as I go slow and keep the spool upright usually on the side in a cup. I do not use it for FMQ since you cna not see where you have been. I like it for SID since you can not see the top stitching but the stitching on the bottom makes a nice pattern. Try it you might like it.