I spray baste the sandwich, but for fmq.....I always use a glue stick on bindings, so easy and fast (no more pins) and it washes out just fine, nothing left to make the binding stiff.....Spray basting and glue (whether bottle or stick) are all designed to wash out, so there is nothing left to affect the feel of the quilt.....I always wash my quilt as soon as the bindings are sewn down - it washes out any starch, glue, spray basting, and any dirt or oils from my hands.....It also will help any areas needing attention be seen.