If pen pressure is not working in Adobe Photoshop, this can be caused by a few incorrect settings in Photoshop, a driver issue, or a windows ink issue. Please follow the instructions below:
1. Double-check to make sure pressure is turned on in Photoshop.
2. Select the brush tool.
3. Press the F5 key on the keyboard, this will open the brush pallet window.
(Note: The brush pallet window can also be opened by going to View on the menu bar and selecting brush pallet.)
In the brush pallet window, select “Shape Dynamics” and make sure the selection box tick in for this section. Under the “Jitter” section, use the dropdown menu next to control to select “Pen Pressure”.