Hhmmm, I'm not sure why no one has answered this. Was it answered in another topic or do you still have this problem?
If so, I have a question. When you say "...it doesn't make anything" I'm not sure what you mean. Do you mean that the object that's filled with the pattern is not affected by the blending mode of the layer in which it resides?
I've done a little testing, since I'm not very familiar with the blending modes. First I learned that you have to have an object under the object with the pattern, and in a lower layer or sublayer. I guess that's because it needs something to blend
with. Also, it appears that the background color (as applied with Doc Prop) does not appear to affect, or be affected by, the blending modes of any layer.
And also I learned that the blending of objects in the layer or sublayer, will only be blended with objects in layers below the blended layer. I can't seem to make it blend with layers above, so I think either blending with objects in layers above can't be done, or that there's some other trick which I haven't learned yet. Also, sometimes, depending on the colors and color values involved, certain blending modes have very little effect. So sometimes it might be working, but not be very noticable.
And finally, sublayers are always and only located below the parent layer. And changing the blending mode of the parent layer does not affect the sublayers, if there is no overlapping object in the parent layer.
Does any of this help? If not, maybe others will have an idea
