Just a few drops is all that's needed for your smartphone or tablet to recognize your gloved gestures. And while the liquid might stain lighter colored fabrics or yarns, it's completely invisible on darker materials. It's not permanent, though, you'll need to reapply the AnyGlove elixir as often as every few days depending on how active you are in your gloves. But a single $15 bottle should last until the warm summer returns. More here.