Retrospective post following tutor feedback.
14 March 2017. In her feedback to Assignment 5 my tutor suggested that I rearrange my blog for Part 5 of the course for easier cross-reference in assessment. Since doing this with the existing blog posts would in my opinion produce more trouble than clarification I decided that I would produce retrospective posts fitting the project exercises in the sequence of appearance in the study guide (Open College of the Arts, 2011, pp. 123-134). I apologize for double-posting images already contained in the posts covering the work for my assignment pieces.
So, here is my exercise work for testing the impasto technique of applying paint. In Part 3 of the course I had already started using my palette knives (Lacher-Bryk, 2016a) (Fig. 1). After an awkward start I had found them increasingly good and easy to use:

Also part of my preparatory work and assignment piece for Assignment 4 was mostly painted using impasto (Lacher-Bryk, 2016b). The finished result unfortunately suffered from a deplorable longer-term change of colour in the black paint I had used then (it turned a very unfortunate indifferent dark grey after I had taken the photo, which swallowed all the beautiful elements visible in Fig. 2 below), but I was quite happy with the structural quality of the rocks produced. I also noticed that my confidence in using palette knives grew quickly:

For the present exercise I first produced an intuitive multi-layered impasto piece, in which I examined the emergent properties of depth and light effects. This 56 x 42 cm acrylic paper would later become the background for one of my Assigment 5 pieces (Lacher-Bryk, 2016c) (Fig. 3).

Next I produced some monochrome structured layers on 42 x 56 cm acrylic paper, first using acrylic medium only on top of a dried white background (Fig. 4), then using acrylic paint directly (Fig. 5). The structures were created using two different kinds of large serrated spatulae. Both the exercises below were later used in my Assignment 5 project “A Shadow on his Soul” (Lacher-Bryk, 2016d):


Some more impasto effects I also tested in preparation for my third Assignment 5 project. In particular, I mixed finely grated willow charcoal into white acrylic paint and applied it with a palette knife. The charcoal dust mixed with the paint to give a wonderful cool grey, while the larger pieces moved with the direction of the palette knife to produce a very attractive pattern (middle row in Fig. 6 below. This type of mix I later used to prepare the background layer for my third assignment piece (Lacher-Bryk, 2016e).

Impasto for me is an incredibly versatile technique, which I will without any doubt come back to regularly with great joy.
References:
Lacher-Bryk, A. (2016a) Part 3, project 1, exercise 1/2: Portrait and Figure – drawing the human figure, linear figure study [blog] [online]. Available at: https://andreabrykocapainting1.wordpress.com/2016/07/18/part-3-project-1-exercise-12-portrait-and-figure-drawing-the-human-figure-linear-figure-study/ [Accessed 14 March 2017]
Lacher-Bryk, A. (2016b) Assignment 4: “Claustrophobia” [blog] [online]. Available at:
https://andreabrykocapainting1.wordpress.com/2016/11/29/assignment-4-claustrophobia/ [Accessed 14 March 2017]
Lacher-Bryk, A. (2016c) Assignment 5, subject 1: “A Shadows Only Painting” (including Part 5 project exercises) [blog] [online]. Available at: https://andreabrykocapainting1.wordpress.com/2017/01/15/assignment-5-subject-1-a-shadows-only-painting-including-part-5-project-exercises/ [Accessed 14 March 2017]
Lacher-Bryk, A. (2016d) Assignment 5, subject 2: “A Shadow on His Soul” (including Part 5 project exercises) [blog] [online]. Available at: https://andreabrykocapainting1.wordpress.com/2017/01/21/assignment-5-subject-2-a-shadow-on-his-soul-including-part-5-project-exercises/ [Accessed 14 March 2017]
Lacher-Bryk, A. (2016e) Assignment 5, subject 3: Hans Christian Andersen “The Shadow”. An attempt at an illustration (including part 5 project exercises) [blog] [online]. Available at:
https://andreabrykocapainting1.wordpress.com/2017/02/02/assignment-5-subject-3-hans-christian-andersen-the-shadow-an-attempt-at-an-illustration-including-part-5-project-exercises/ [Accessed 14 March 2017]
Open College of the Arts (2011) Painting 1. The Practice of Painting. The Bridgeman Art Library, London, New York, Paris, pp. 123-134.