Thanks everyone! I have been able to pick some of it off (combination of knife, toothpick and/or fingernails). Some I coloured over with a red or a black marker - TRUE STORY! Because the fabric is batik, it doesn't show the marker (much).
I am now going to test a leftover fabric swatch with acetone. I don't have a green marker.... and there are some spots where it is impossible to 'pick' or 'markerize'.
Lesson about glue learned.
