These pens have saved my life. They are wonderful and I love them. I am working on an applique quilt. I trace the pattern directly onto the block using a light box. That way I know how to place the pieces. Then I trace each piece with each different fabric and do the applique. Having the pattern already traced onto the backing block fabric is almost more helpful than the tracing of the shape. I love them and don't know what I would do with out them now. My lines show a LOT as things move around - and I just iron everything and voila!