The bristles are firm and great. This is exactly the brush I wanted. I bought it to do tightline eyeliner.

THEBOON

Flat multi brush

This brush is thin and small, making it very versatile. I bought it as a replacement for the Picasso 722 which broke, and I found it to be quite similar when used. The vertical length is shorter, and the horizontal length is just a bit longer than the Picasso 722 brush.

It does feel a bit stiff, which might feel irritating to some, but if you use it gently, that issue is resolved. Overall, I'm satisfied.

Its small and thin design makes it really useful for drawing eyeliner with shadow. I hope it doesn't get discontinued because it's also great for shading the aegyo-sal area.
I plan to repurchase if it breaks. I like it.

Hmm... The straight shape makes it comfortable to use. If you're a beginner, it helps you draw thin lines well.

The brush is flat and thin, making it easy to create detailed looks.

I bought the liner brush first and loved it so much that I ended up getting the flat brush from THEBOON too! Super satisfied with both.

I really, really love this. I need to stock up on a few more.

I got this to apply eyeshadow as a liner. The flat shape makes it really easy to use, and I think I'll reach for it a lot! The price is great, and I love the unique design from THEBOON!

I got this because I wanted to use eyeshadow to draw precise lines! The brush is thin and looks like it'll work perfectly, so I'm really happy with it. I've picked up a lot of great brushes from THEBOON, haha. Definitely recommend!

It's definitely on the smaller side, so it gives you really precise lines. Perfect for under the eyes and lining your eyes.

Thin but sturdy—just what I needed! There are lots of slim, small brushes out there, but most of them are too flimsy or the bristles end up spreading out. THEBOON's brush is really firm! I'm planning to use it for eyeshadow details or as an eyeliner brush. I can already tell this will be a staple in my routine!

I got this to make applying eyeliner easier~

I recently got into tightlining, so I picked up this brush from THEBOON. I usually use Picasso brushes, but I was curious about this short bristle one and decided to give it a try!

I haven't tried it yet, but I picked it up because of all the positive reviews. I do wish THEBOON included a brush cover though. My other brushes came with covers, but this one didn't, so it's a bit inconvenient since dust gets on it when I store it.

Wow, this is the brush I use the most out of all my brushes! It's fantastic for lining!

I always use shadow to draw my eyeliner, so getting a natural, thin wing was tricky. But this THEBOON brush is super thin and firm, so it glides on really easily! 

If I have to point out a downside, it's not very soft—it's actually a bit rough and stiff. If you use it under your eyes or for anything else, it might feel a little uncomfortable.

Honestly, I can't think of any other use for it except for drawing the tail of my eyeliner. I got it for a bargain using coupons and points that were about to expire, but I don't think I'd pay full price for it.

That said, really soft brushes don't pick up shadow well and tend to kick up a lot of powder, so maybe it's actually a good thing that this one's a bit stiffer.

Recently, I've gotten really into filling in my waterline, but I didn't have the right brush for it. So I picked up this one from THEBOON, and it's perfect! It's dense and firm, which makes it just right for the waterline. I'm planning to take good care of it so it doesn't shed or get clumpy. It's also awesome for lining because it's thin, firm, and glides on super smoothly. You can even use it to make a wing with your nail! I'm 10000000000% going to repurchase. If there's a big sale, I'll definitely stock up. There's a wider version of this brush too, and that's next on my list! Thanks for making such a great brush, THEBOON!

The bristles are short and firm, so it's easy to draw eyeliner smoothly with this brush.

I don't like my eyeliner to look obvious, so I usually just use gel liner on my waterline. I wanted a brush that's thin and short, and this one from THEBOON is exactly what I needed.

I had this in my cart for a while, going back and forth on whether to get it, but as soon as THEBOON had a sale, I grabbed it right away! I bought it along with the Slim Edge brush, and I’ve included comparison photos. The Flat Multi is on the left, and the Slim Edge is on the right!

This brush from THEBOON is perfect for applying eyeliner! The shape is just right and makes it really easy to use. It does sting a little when I use it on my lower lash line, though...ㅠㅜ