Combining Art Brushes and Width Tool

Thanks all for the great tips, I'm suprised by how quick the qualitative input arrived.

For future reference; I did get the best result using these steps;

1. create the variable width stroke (width tool) first with a solid stroke
2. save the variable width as a variable width profile (bottom of stroke panel)
3. create a long art brush (rather than a pattern brush; the pattern brush is easier to manipulate, but leaves unwanted gaps)
4. apply the art brush to the stroke
5. apply the previously saved variable width profile

The result is a mathematically looking pattern width a consistent stroke width (because strokes werent expanded)

Hi, I got some rather confusing results from an art brush with the width tool, but nothing quite like yours. However, I had a good result with a pattern brush (on the left), so perhaps you could try that:

The width controls work fine for other art brushes though. I'm not sure what goes wrong with this particular one.

I do get somewhere expanding the brush and the using the Warp Tool to shift it in place. But then I use the mathematical feel it has now because lines get jagged a bit.

Did you outline the strokes before creating the brush?