These pens are absolutely my favourite marking tool for bag making and sewing projects. Size: 0.7mm
Write on with this smooth writing gel ink, with no smudging or fading, and then simply touch with a hot iron to remove colour.
Always test on scrap fabric first. Sometimes certain colours will leave a light white residue on dark fabrics. Because this is thermo sensitive, the ink can come back in freezing temperatures.
I LOVE this product and use these pens to mark pleats, mark lock placements, and trace templates; however am still careful not to mark up the fronts of my bags or projects with them. These are recommended for the wrong (back) side of fabrics only. If I mark something wrong, a simple touch of the iron will take it off. Some people recommend these for red work or quilting, but I do not recommend that.