Oh sure, I just didn't know if anybody was interested.
it's just a matter of using the tilt feature of Rebelle and let 'nature', or physics, do their thing.
i use a brush with high wetness, obviously, pause the diffusion and apply the paint and let the two colors touch themselves, you could let them overlap completely or just a bit, it's up to you and this leads to various degrees of effects.
anyway the main ingredient is the tilt feature, a high amount of it makes the water naturally flow, so when you un-pause the diffusion the wash happens and the colors mix.
I am not on the pc now, so I will be more specific or even post a small video later.
One account,
many possibilities