The 505 spray was not old, I just purchased it. ( I do not know how long it was in the store, but it is a very busy store) I would have to say it was well shaken, I think I would have shaken it the same each time I sprayed it.
I don't understand why it would be a dye issue. I used the same material for other runners (I had 10 meters of the same material). The stain is not similar to a bleach stain. The stain looks like a large wet mark.
Now that I have thought about it, I wonder did I spray it too close to the fabric? Did I spray too much in one spot? With those "operator errors" taken into account, could that have caused it? (I can probably test that myself) shouldn't it still have dried, or at least washed out?
I think the bigger lesson I learned from this - is to spray the batting, not the fabric. Is that the correct way?
Dee