How to change the roundness and size of a brush in Adobe Illustrator?

Question

When I try to use a calligraphy brush the roundness and the size doesn't change to another option.

1. I go to Brushes Library Menu → New Brush and select the Calligraphy Brushes
2. The Calligraphy brush menu pops up with three main options: Angle, Roundness and Size.

It's not allowing me to change these options, what am I doing wrong?

Why can't I change the brush options in Adobe Illustrator?

Answer 1

When creating a new Calligraphic Brush you need to type the Angle and Roundness, you have a slider only for the Diameter that you can drag and these CAN be edited even if you have them Fixed and not Random.

You need to change to Random only if you want to add a Variation to the brush.

What is variation?

helpx.adobe.com : Enter a value in the Variation box to specify the range within which the brush characteristic can vary. For example, when the Diameter value is 15 and the Variation value is 5, the diameter can be 10, or 20, or any value in between.

PS: If this doesn't help, please create a print-screen of how your Calligraphic Brush Options looks like.

Answer 2

If you are referring to the "variation" options on the right, you need to first change the Fixed drop down to something else, like Random.

Be aware many of the dropdown options are not available without a tablet.