Nail Art Pens
I bought these double sided pens at a online bidding site (Tradera) which is kind of like a Swedish Ebay. Thats a good tip for finding things a little cheaper than usual. Just be prepared that it might not always be the highest quality. I just swatched all of my 38 nail art pens that I bought and some (maybe 5) are a little damaged at the brushtip, but thats just something you have to live with. I sure have plenty anyways.