I purchased my first Sigma brush in June, and have since then bought 3 more because I liked it so much. And after using them for the last couple of months, I feel like I can write a review as to how fabulous they are.
Sigma brushes are relatively hard to find because they are only sold online on the Sigma website. But their website does ship internationally. You can also purchase them on Amazon (as I do) for slightly more per brush but free shipping if you have Amazon prime.
Despite the fact that these brushes are not available in stores, they seem to be really popular. A lot of people say that they are an inexpensive version of MAC brushes. I don't own that many MAC brushes (or brushes in general) so I can't compare, but by themselves, Sigma brushes are some really awesome products.
The F82 is a round kabuki brush from Sigma's Sigmax collection and is $21 on their website. I actually purchased this brush thinking it was going to be very different. I wanted a powder brush that was similar to the Elf Studio Powder Brush. And this is definitely not for powder. It is very soft and dense and much smaller than a powder brush, making it perfect for applying liquid and cream face products. It blends everything out very well, giving your face a nice, streak free finish.
The E25 is Sigma's eye blending brush for $12 and probably their most popular one. It is often mentioned as a dupe for the MAC 217. This was also the first brush that I got from Sigma and I was so gosh darn impressed that I bought my other brushes. This is the best brush I have ever used to blend out shadow. It diffuses harsh lines so nicely that I can't even describe it. I don't have anything bad to say about this brush other than the bristles tend to splay out after you wash it a couple of times. But the brush still works perfectly.
This one is the smaller tapered blending brush. The larger size is the E40. But I find it hard to imagine that anyone's crease areas are that big. Because this smaller brush is already slightly too large for precise crease work on my eyes. It costs $12. And the biggest problem that I have with this one is that it sheds the most. I seem to lose about 1-2 hairs every time I use it. And that's not traumatic but once a brush hair fell into my eye and that was not a party. I would really like my eye brushes to stay intact. This is a good brush, but watch out for that.
This is the eye shading brush and costs $12. There is also a large version of this brush, the E60. But as with the crease brush, the one I own is already on the large side so I would definitely not go for the E60. This is a pretty basic brush but it does its job well. I used it to pack shadow on my lid, and occasionally for my highlight colour. It doesn't shed. Overall, a good brush to have.