No advice for the invisible, but I will say that my friend and her group uses the 90 or 100 weight thread that is the closest match to the color in each piece she is sewing down and a teeny zig zag stitch and you have to get really close to see it.
Last edited by QuiltnNan; 10-11-2019 at 04:35 PM.
Reason: shouting/all caps