The borrowed Italian word impasto most commonly refers to a technique used in painting, where paint is laid on a small area of the surface or the entire canvas very thickly, usually thickly enough that the brush strokes or painting-knife strokes are visible. This tutorial will show you how to create your own impasto-effect artwork.

Load the image you want to work on and apply a Random Painter filter from Building Blocks/Simple Styles. 

Select the Random Painter layer and in the Properties+Preview pane change the brush type: use "Invoke the brush selector" by clicking the Browse button.

Choose the Palette Knife 02 brush from the brush selector window and press Ok to use it. If you do not have an appropriate brush for your project you may want to download some from here. If you want to import new brushes that you already have on your computer, click here to see how. 

The Palette Knife 02 brush has been applied to the work. The preview window has also refreshed showing the new brush.

Change the brush's size depending on your image size. A larger or a smaller brush width and length may fit better. You can also increase the number of passes, coverage, etc for a more pleasing result.  To obtain a more realistic impasto effect in order to see the brushes strokes better, add the Emboss filter after the Random Painter from Building Blocks/Basic Image Processing. You will obtain a so-called chained layer.

You may now adjust the Emboss filter's properties. The preview image will immediately be updated. Now add a Texturizer filter from Building Blocks/Simple Styles to add a canvas to the image for a yet more naturalistic effect. 

Note: You can obtain a similar result using the Simple Strokes filter. Inserting a Strokes Direction filter before the Simple Strokes is recommended so that the brush strokes correctly follow the directions you intend. In this case, inserting a Sharpen filter after the Simple Strokes to emphasize the brushes is also recommended.

In order to emphasize the painting effect, it may be usefull to add a Reveal Original filter above the previous layer. 

Adjust the Reveal Original filter's properties by changing the Brush family and the number of strokes if needed. 

The final result using the Random Painter is :