I use hand quilting thread for basting----By mistake several years ago, before I even thought about quilts or quilting, I bought some Coates & Clarks hand quilting thread.
The first time I basted a quilt I started out with just regular thread and that was NOT working very well, so I tried the hand quilting thread and it does hold everything in place very well...no puckers!!!
I have only done up to twin size so that may make a difference.