The reason why Illustrator brushs don't work well

[정현28961606wrfp]

Hi! I  just downloaded a brush pack for Illustrator for the first time.

I have been using Illustrator for a long time but never changed brushes, so I don't know about how it works well really.

When I applied the new brush, it makes some lines like a below image.

Please let me know how to solve this problem, Thanks!

[Monika Gause]

The brushes are creating those lines. So what exactly do you not like about that? Those lines should have been shown as a preview for that download, no?