@Eva
I'm using PS CS5.
Photoshop on Mac should not have that problem. Are you using Windows version?
If so, you may have to get a plugin called Lazy Nezumi Pro to smooth out the lines. That plugin is unfortunately not free.
Have you tried other software? Medibang Paint Pro, Krita. Test them to see if it's a hardware issue. If not, then maybe it has got to do with Photoshop. I see this sort of problem occasionally but I can't remember with which brand or model since I've tested too many to remember.
@Eva
I'm using PS CS5.
Photoshop on Mac should not have that problem. Are you using Windows version?
If so, you may have to get a plugin called Lazy Nezumi Pro to smooth out the lines. That plugin is unfortunately not free.
Have you tried other software? Medibang Paint Pro, Krita. Test them to see if it's a hardware issue. If not, then maybe it has got to do with Photoshop. I see this sort of problem occasionally but I can't remember with which brand or model since I've tested too many to remember.