You can adjust how Mudbox responds to pressure sensitivity from a Wacom tablet and stylus by adjusting the Min Size and Min Strength properties in the Advanced section of the tool properties.

Min Size specifies how small the tool size is when the lightest pressure is applied to the pen. Min Strength specifies how weak the tool strength is when the lightest pressure is applied to the pen.

Adjusting the Min Size and Min Strength properties to their maximum settings makes the pen function without pressure sensitivity, similar to a mouse. This can be useful if you need to repeatedly sculpt features at exactly the same height or width on your model.