This might be a function of your operating system and tablet driver rather than just Photoshop, but I am not entirely sure because of the timing of the different components.
Can you tell us what operating system you are using?
And what tablet?
Where did you source the brushes? If you can give us a link, we can test.
Note, that Photoshop brush management changed with CC2018. The biggest change is that Photoshop can now store tool presets along with brush presets, and show them in the brush menu. Photoshop has always (well for a long time AFAIK) been able to use tool presets, but you had to access them via the Tool Presets panel (i.e. the Impasto brushes by John Derry and Kyle Webster). I would think that the bottom line as far as CS6 goes, is do the brush sets have an ABR or TPL file format? Both should work, but the TPL files are used differently.
My Operating system is windows 8.1 and I use XP-Pen Star 05 Tablet.
I thought it was a tablet issue at first too but when I tested it out on Photoshop CC2018 Trial it worked great with the pressure sensitivity.
When I open the brush set on CS6 there is no pressure variation at all. even in the thumbnails.
I downloaded the brush set from the adobe products page:
I don't know about that tablet, but with Windows 8.1 it is worth trying to force the tablet to use the WinTab API (an API is a bis a bit of software that interfaces one thing with another — or so I am led to believe)
Check out the Tablet set up help link on the Overview tab of this forum.
Use Notepad to create a text file with the single line
and save it as
Here's where it gets tricky as the guide gives details for CC 2015, and you are going to need to work out the equivalent folder for CS6. I think it should be obvious though.
3. Save the file as a plain text file named PSUserConfig.txt in the Photoshop settings folder: [Installation Drive]:\Users\[User Name]\AppData\Roaming\Adobe\Adobe Photoshop CC 2015\Adobe Photoshop CC 2015 Settings\
Note, you will need to make Hidden Files viewable in order to see the App data folders
Give us a shout if you get stuck, and good luck