Is it possible to use brush pressure in Adobe Illustrator using a mouse only, not any external devices like drawing tablets?
I asked because I cant change the "pressure" in the brush tool settings.
This is already answered but I wanted to explore another alternative.
Some programs rely on the velocity to simulate presure. For example take a look at MyPaint where depending on the vlocity of a stroke the width chanves (on some brushes) http://mypaint.org/downloads/
You could later vectorize thoose strokes.
If you don't be afraid to run experimental software that is available on developer's web forums, then Google "Pressure sensitive mouse". You will get for example this hit: https://github.com/rfc2822/GfxTablet/pull/34
The discussion reveals that the problem "how to input pressure data by the controls of mouse" is not an easy programming task to solve. But some demo versions there are done as from programmer to programmer, not as a solid publishing ready product.
I haven't tried them. Do not it you either unless you have a different experimental machine or a solid, disk image based and in practice proven way to restore your system. NOTE: Windows restore points are not a solid disk image based system backup.
BTW: I have not tried a graphic tablet & pen with Illustrator. I do not know, which drawing tools really respond to pressure changes as you draw. I have loaned one for short time and tried it with Photoshop. There it worked perfectly when I painted.