Teeny tiny folds, such as those along the edge of patch pockets, seem to me like an accident waiting to happen. Holding the fold with the fingers of one hand, pressing with a hot iron in the other. Ouchie! Plus, maybe it's just me, but I often struggle to keep the fold consistent, especially on a long piece. We tested the Clover Fabric Folding Pen and found it to be a handy way to create more exact folds for patchwork, hems, cuffs, pockets or anywhere a small exact fold line is required. The pen draws a liquid line, and the special liquid solution ever so slightly weakens the fabric's fibers along that drawn line. Not enough to damage the fabric; just enough to allow it to easily crease. It doesn't work on all fabrics, but on the ones it's appropriate for, it is pretty darn cool.
The most important thing to remember is to test the pen on a scrap of fabric first. It won't work on impermeable fabrics, like polyester. And, do not use it on any fabrics that would be sensitive to spotting.
You simply remove the cap of the pen, fill it with water and add about 4-5 drops of the marking solution. The easier the fabric is to penetrate, the fewer drops you need. Replace the cap and you're ready to draw your fold line. As you screw the cap into place the liquid will flow into the pen point.
Use your see-through ruler to figure out where your fold needs to be.
Draw a line with the pen along the edge of the ruler. You need to squeeze the pen slightly for the liquid to flow. Don't squeeze too hard; bending or shaking the pen may cause it to leak.
Remove the ruler. Wait just a few seconds to make sure the liquid has penetrated, then fold along the drawn line.
When it dries, the original line is invisible, and the folded edge stayed as if it had been pressed.
But again, as I mentioned above, I don't recommend trying to use it on fabric that is prone to water-spotting. It worked great on the quilting cotton and cotton duck we tested it on.
After you've drawn a line, always set the pen point-up rather than simply laying it down on your work surface. A pencil cup makes a good holder. When you're completely done using it, drain out all the liquid before you put it away.