Following this great tutorial by Gigantic about creating "grainy gradient", I face a problem after masking.
I have two layers: 1st one is the object itself which is a [Rectangle] and another Group including paths. As mentioned in the video, I select the group, then in the "Transparency Panel" I create a mask and then copy the object in the black box. Everything works well except the opacity of brush paths. I'm not sure if it's related to the brush or is a bug - maybe. I don't have this problem with general brushes.
Ticking "Invert Mask" helps a little, but the opacity isn't still 100%.
I'm using Spoon Graphics Stipple Shading brushes from the free bundle.