How to outline a brush in Photoshop
Is there any way to add an outline to a brush so that when stroking a path it will give a sense of depth and layering where the path overlaps?
As an example, here is an image of footprints. How could I add depth so that you can tell which footprints came later on (i.e. on top of other footprints)
I'm going to answer this question based on the comment thread that happened on a deleted answer, where Sean said:
Thanks, but what I mean by depth isn't the bevel and emboss 3D, I just meant layering; how it makes one footprint look like it's on top of another.
There are numerous ways to create a sense of "depth". As Scott mentioned, opacity is one technique. Any elements towards the bottom would have a lower opacity and elements stacked on top would have a higher opacity. The only draw back is that earlier footprints may be difficult to see and eventually, you will reach a maximum opacity.
Another alternative is to use different layers of footprints (separate the footprint paths based on walking from point A to point B.) Then you can add layer effects to emphasize depth. This includes drop-shadow and stroke. This approach takes a little bit more work, but you'll have more control over the result.
In the end there isn't a one-click solution that'll make your dreams come true (yet). for now you'll have to do some manual work to achieve the depth that you want to see.
Something else I might suggest is using less footprints overall, as it looks pretty cluttered as-is.