Create a simple style as shown in section 2.2 "Create a Simple Style with a single filter" and select a second style from the Styles tab. We have chosen Outlines with Scanned Brush from the Building blocks/Simple styles folder. Choose whether to add the second style above or beneath the first applied style (in our case Random Painter). There are three different ways to apply the selected second style to the image:

•    Drag and drop the styles into the highlighted area either above or below the layer.•    Shift + Double Click the style to insert it above the selected layer or Shift + Ctrl + Double Click the style to insert it below the selected layer.
•    Press Shift + Enter to insert the style above the selected layer or Shift + Ctrl + Enter to insert the style below the selected layer.

For styles dropped above or below the previous style, PostworkShop automatically creates a new layer in the Layer Browser since they are applied in parallel and have to be blended.

Select the layer with the properties you want to adjust (e.g. “Outlines with Scanned Brush”), it will appear white, while the other layers remain gray. Switch to the Properties + Preview pane and set the style's properties by dragging the sliders to the desired values. We have chosen to change the Brush type for the outlines: spotty Ink 01 from the Ink category.  

The Progress Bar shows the percentage completed. You can always cancel the rendering process by clicking Abort or using the Esc key. 

We will also raise the Brush width to 28 and change the Detector type for the outlines from Sobel to Sketch 2. The result will be:

You can add and layer as many styles/filters as you want. For example, add a Mozaic filter above the other two layers:

The styles can now be blended. Select the layer you want to blend with the layer below - Mosaic in our case - and choose a blending mode, e.g. "Overlay", and adjust the opacity of the layer if necessary. The resulting image is rendered in real time.
Note: we have not blended the Outlines with Scanned Brush with the Random Painter layer because the outlines are already on a transparent background. 

If you wish to remove a layer, select it and click the small trash can icon below the Styles Layers browser. The layer with the style applied on it will be removed. 

The final result with the Random painter and the Outlines styles applied is: 

You can now download the PostworkShop project file of this tutorial by clicking here.