Great idea ..... sometimes the obvious, just is not obvious!
And now I have a visual of you up in the middle of the night, blow drying your quilt!
MiraB ... I too have noticed the ghost marks with the Frixxions. Looking very close, I have even been able to spot them on white fabrics. I haven't noticed it more/less according to the ink colour ... must pay attention!
I love the Frixxion pens because of the fine line ... I just consider the ghosting factor and whether I want to use it or not.