Like the femme fatale in a film noir, I have a love/hate relationship with the protagonist in this story. This brush is the best I've found. It's got spiral bristles and it's thinner than some of the others I've used. (In the photo below, the Hourglass wand is on the left and the one on the right is Bare Minerals - reviewed on 12/9/11) So thin, in fact, that I can use it on the backside of my lashes to give them even more volume. It gives really nice volume and separation. So, why the hate? It smudges :-( I tried making excuses for it - it's my eyeliner, I put on too much eye cream, etc. - but I finally had to face up to reality. The good news is it got me thinking about how you love part of some products sometimes but not the whole thing. So, I thought about using the brush from this mascara in another one where I like the formula but not the wand. Brilliant, no? Sadly, the opening is smaller than on most mascaras. It could be done with almost any of the others I have but not this one. Oh well, I guess the search continues!