At this point we have a single stroke on its own layer. Creating the spiral is done by replicating this layer and transforming it, shrinking and rotating. By applying this same transformation to each subsequent layer, we create a progressive change that generates our spiral shape.

It can be easiest to create a new Action to handle this for us. That way we can just play the action repeatedly and see how the spiral progresses.

• Make sure your stroke layer is selected.
• In the Actions palette, select New Action. The system drops immediately in to record mode.
• Duplicate the layer your stroke is in.
• Select Edit/Free Transform (Cmd/Ctrl + T) on this new layer.
• In the numeric entry boxes of the top control bar set the transform scale to 90% width and height, and layer angle to 10 degrees.
• Hit enter to okay this (you may need to hit enter twice, once to okay the text edit change, once to okay the transformation).
• Press the Stop button on the Actions palette to stop recording.

You've now got an action that will help you create the spiral. The slight down scale means that as we duplicate the process the stroke will shrink inwards as it rotates. Activate your action a few more times, we applied it 20 more times.

As you can see from our spiral, the result may not always be circular. If the area of your strokes is not roughly square you may end up with a flatter spiral. The scale and rotate values also have an effect on this. You can experiment by making either width or height scale differently, or rotating in large chunks of around 30 degrees so that the spiral intersects itself as you apply. Scaling just a small amount, say to 98% size each time, can give you a very detailed result..

By now we have a spiral against a white/black background. We're going to give it a more interesting background and a shadow for some sense of depth.

The shadow needs to be created from all of the layers that we duplicated.

• Add a new, empty layer just above the Background.
• Now Cmd/Ctrl click the first stroke layer to select its contents.
• Hold down Cmd/Ctrl and Shift, and click each of the other stroke layers to add their contents to the selection.

When you have done this to all of the layers, make sure your empty layer is selected and from the Edit menu select Fill, and fill with Black. Make sure that the Preserve Transparency option is turned off, or you won't see anything appear. You should now have a black shape that represents your spiral (though you will probably not be able to see it under the spiral itself). It's time to turn that in to a subtle drop shadow.

Before we apply the blur, we're going to duplicate that layer so that we can use it layer on. Duplicate the layer you just filled, and hide the duplicate.

Apply a Gaussian Blur to the original layer, radius of 2. This immediately gives the spiral a sense of depth. We don't really need to offset it, but let's give it a slight angle by selecting the Move tool and using the arrow keys to nudge the shadow down and right 1 pixel each. Then set the Opacity of the shadow layer to 80% so that it's not too harsh.

You should now have something that looks a bit like this.

One trick that can make the background quite interesting is to construct a pattern using the spiral itself. To do this we use the duplicate layer that we created before applying a blur to our shadow layer. Hide the stroke and shadow layers for the moment, and show the duplicate layer we created.

Select the background layer and we'll add a gradient. With the gradient tool selected, set the Foreground colour to RGB 198 and the Background colour to RGB 127. Apply a linear gradient from top to bottom. Now reselect your duplicate layer and we'll apply some effects to it.

• Apply a Free Transform to this layer (Cmd/Ctrl + T).
• Scale the layer up by holding down Shift & Alt and dragging one of the corner handles outwards.

Holding down Shift means that the layer will not change aspect, and Alt means that it will scale from the centre outwards.

• When you have scaled it up around 400%, apply the transform.
• We've now got a very big spiral in our window. Move the layer around until you see an interesting part of it visible.

Because we want this to be in the background, we need to fade it and apply a few tricks to make it look less solid.

• Apply a Gaussian Blur of 8 pixels.
• Add a new layer beneath it and fill that layer with white.
• Merge the blurred layer down on to the white layer.

We need to do this so that we can apply a Curve.

• Open up the Curves Window (Edit/Adjustments/Curves, or Cmd/Ctrl + M).
• Apply a clamping curve in the same manner as the previous one we applied. The curve can be roughly the same, we're after a 'blobby' effect.

Depending on the choices you made with positioning, we've now got a more interesting background. Show the spiral layers and the shadow layer again and we're done.