I bought this product after reading reviews that said it could be used to turn existing eyeshadow into eyeliner. The sticker on the product said to load the brush with powder and then apply eyeshadow, but when I did, it left a smudge-like residue on my eyeshadow. Well, I figured it might happen about half the time, so I only used the edge of an eyeshadow I wasn't particularly fond of, so it wasn't a big deal. But be careful not to do it with your favorite eyeshadow. You could either load the brush with powder thoroughly and then apply Aqua Seal, or, even though it's a bit wasteful, scrape off some of the eyeshadow with a spatula. With the former, you can't add more eyeshadow later, and I feel like I'll end up scraping it off again, so I'm thinking it's better to scrape it off from the start. Depending on the eyeshadow you choose, you can create unusual eyeliner colors, and you can use strong, pigmented eyeshadows or darker eyeshadows that don't wear off easily, so I'm happy with it. I think makeup lovers will especially enjoy it. I also like the eyeliner itself, as it doesn't look too harsh, but rather has just the right thickness and texture, as if it was drawn with a gel liner and then slightly blurred.