Hey lolozori,
I'm glad you like my brushes. I've spent a lot of time experimenting with this brush engine.
You cannot create this fake water effect in Oils & Acrylics. Only in Express Oils. I tried. This is because you need to select the option for "Use for Stroke" in order for this to work.
But, that option is grayed out for Oils & Acrylics brushes (below)
Side note: Did you know that you don't have to recreate your brushes for different categories? If you made a cool brush in Express oils, just right click on it > copy brush preset > navigate to your oils and acrylics tool > right click > paste brush preset.
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Here are a few tips for your Sumi Bristle brush:
1. You don't need 3 brush tips. Delete the third one.
2. You have a good idea in using the same brush tip twice, but flipped upside down on the second one. But if you want the hard edge to show up in the same direction no matter how you make your stroke, you have to choose "pen tilt" instead of "pen pressure"
With pen tilt, the hard edge will always be on the same side, and if you want to change the direction of the hard edge, you have to actually tilt your stylus in the opposite direction. On one hand your strokes will be uniform, so you have more control, but its awkward to paint the other direction. With pen pressure you get variability but with a lack of control (unless you keep in mind how to start the stroke ie-left to right for hard edge on top)
Cheers