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So what I'm suggesting is that if, for example, the size and opacity of a pencil is controlled with pressure you could control the range of the opacity through the altitude on the tablet pen. This would mean that you could draw fine dark lines with the pen upright and more nuanced thickness when you pen is more angled. I drew a picture to try and show what I mean.
https://drive.google.com/file/d/0BxEk8T ... sp=sharing" onclick="window.open(this.href);return false;

This is already the case. Indeed, it also depends on your tablet capacities.

I'm on a cintiq. So I can already have the size and opacity affected by pressure, but have the size range restricted at the same time by the pens altitude?

At the same time, it's not possible : you can choose Pressure or Altitude connection, not both.

you can do it if you make an animated brush in which the animation changes the size of the brush.
then connect the animation behaviour to altitude.

Ah ha, I'll look into that next. Thank you!