I have used water soluble basting tape on heirloom sewing projects. It works very well, and I have considered it for basting bindings. The only thing that keeps me from it is the cost - Elmers glue is a lot cheaper :-). The type of tape I had completely washed out of the very fine batiste fabric I used so I am sure it would wash out of a quilt. The brand I used was Wash-A-Way Wonder Tape. It sewed beautifully, even with a 65/9 needle and 50 and 60 weight thread. No adhesive build up on my needle at all. After my experience with on the heirloom projects, I started using it to keep plaids matched up and to do zippers on garments. Can you tell I am a fan?
Pam