Basic line effect (Click the image to see it bigger)
This weeks theme is lines, and it's important to notice that it's "lines" and not "strokes", as strokes isn't the only way to create line, and as evidenced by today's post, not always the best way to achieve the effect you're looking for. With that said, let's not waste any more time on words, read on to get info on today's effect and to be able to download the style file.
Basic line effect
Today's effect is, as mentioned above, not achieved with help of the Stroke effect, but rather with the Inner Glow effect. The reason for this is that I wanted an effect that goes along the inside edge of the object, and interacts with the colors on the object, but even when choosing the "Inside" Position it doesn't. Instead it interacts with the colors on the layer/layers below the object. That gives an interesting effect as well, but not the effect I was looking for today: a basic effect that darkens the colors along the edge of the object. It can be a nice effect for everything from more cartoon-like drawings to header text. And it only takes a very simple style:
Inner Glow settings (Click the image to see it bigger)
To get a stroke-like effect the Choke is set to 100% so it is a solid line rather than a blurry one, the Size is set to 3px to get a nice small line along the edge of the objects. To make it interact with the object color in the way I want it to the Blend Mode is set to Color Burn, and the color is set to black as I want the line to darken the object behind it rather than lighten it/add a color to the effect. It's worth mentioning that on some of the objects I've used the Linear Burn rather than the Color Burn as the latter doesn't seem to work with some colors. I'm sure there are technical/art theory related reasons for this, but I don't know those reasons, I only know that's how it works out in practice. So, if the above settings/supplied style file doesn't work with the color of your object, just change the Blend Mode from Color Burn to Linear Burn and you have a similar effect.
You can get a nice effect by combining a Stroke and an Inner Glow, but the Stroke effect is greedy, so if you choose Inside for it, it takes over the area where the Inner Glow and the Stroke intersects and "punches a whole" through the effect. That said, if the Inner Glow is wider it does give the expected effect in the area where it's just the Inner Glow. For a more predictable result: use the Outer position.