Quote Originally Posted by Magicdesign View Post
Looking at soft erase, it looks like it just roughs the edge slightly. I am looking to create an irregular speckled effect where some is transparent, and some isn't. Like a spray can edge. I can upload an image of what I achieved in the other product, but in the mean time, instead of the brush adding colour, it adds transparency (if you get what I mean)
I wrote this last night:
Yes, it would be useful to have a viewing.

You could create a Scatter Brush along the lines of Novelty > Coarse Spray and make the Line quite wide.
I have no idea if you want a box shape but this handles any shape as well as allowing Transparency of the spray.
I hadn't though of using an Opacity Mask and I came up with Marco's approach.
I stopped at that point as once you Subtract, you are stuck with a fixed shape.

Thank you both @PhilM & @handrawn as your approach retains the means to edit and experiment.
Another arrow for my quiver.

Acorn