The sketch records linear features, placings for trees and other compositional elements, but I also wanted an accurate map of the shadows and tonal contrasts. The castle is built of pale yellow stone and appears lighter than the sky. Trunks of leafless trees stand out brightly in dark shadows. The shadows within the crenellations of the towers are particularly interesting, moving as they do from the inside edge of the battlements to the larger outside face, as the surface of the tower curves away from the sun. It may seem strange to talk of areas of shadows moving, rather than light, but I regard the white of the paper as providing areas of light and consequently work with some line, but mostly in passages of tone or shadow.

A welcome coffee break provided a source of useful additional information in the form of an elderly black-and-white postcard. This certainly helped to explain hidden parts of the building that had only been visible when the trees were smaller and less dense. Fortified, I hurried back to my vantage point and picked out the line of an inaccessible parapet that had previously made little sense in the drawing. I should explain that I like to ‘know’ my subject matter visually before working with it. Even though various nooks and crannies may not be visible from the viewpoint chosen. I enjoy knowing what happens around the corner. A pleasantly warm summer had enabled me to spend some time studying the castle from a rowing boat on the Avon.

Back in the studio, the drawing of the castle forms the central part of what has become a much larger composition. I transferred the drawing, without any changes of scale, to the centre of a 29” x 43” Daler line and wash watercolour board (fine), which enabled me to extend in all directions as the need arose. I wanted a large expanse of sky with plenty of movement to contrast with the stillness of the river. Consequently, I needed a large expanse of river in the foreground. The trees and buildings along the banks were added after further visits to the bridge. I collected more information than I needed since I eventually decided against including more of the very large trees in the foreground. They tended to shift interest from the castle to themselves, but I needed some branches to provide a point in the foreground against which the space beyond can be measured.

Procedurally, I do not think that I have anything amounting to a routine, except that I often paint the sky first. Different paintings require different approaches and it would be difficult to set down a course of action that is largely an intuitive response to the subject matter. This time I have protected areas of the white card with masking fluid. There are many plays of contrast that I want to exploit in the picture:  the light castle against the darker sky, light branches overhanging dark water and dark branches against bright grass. I do use body colour occasionally, but nothing can really substitute for the glow of a white surface through transparent colour. The masking fluid must be thin and runny when used for anything in the region of the sky, otherwise it creates a ridge against which the wash of colour can accumulate, resulting in a residual dark line. If this does appear to be happening resist the temptation to dab it or you will introduce an unintentional cloud! Better to turn the painting upside down on the easel and encourage the colour to run away from the masked area.

The huge sky in this painting caused some concern. The hot-pressed surface of the card has a fine feel to it and may not take much reworking. There is quite a variation in porousness of the surface of different type of watercolour board. This ‘line and wash’ board was one I had not used before and I had to decide whether to wash the sky area over with clean water first, moistening the surface and allowing it a few minutes to soak through evenly before applying colour, as I have usually done with Daler watercolour board.

In the event, experimentation on a waste piece showed that this card would accept a wash evenly without previous priming and, more importantly, would permit colour to be lifted off back to white with a clean damp sponge. Having mixed a saucerful of cobalt and cerulean, the wash was applied with a large sable brush loaded generously with colour before each long stroke. Card is not as tolerant of scrubbing as paper, so the softer the brush and the lighter the touch the better. Working at speed from top to bottom I began to dip the brush into clean water rather than the paint, to dilute the colour as I approached the horizon. I had decided that the structure of the sky should echo the shape of the river and with that in mind I allowed areas of cloud to suggest themselves:  a fluffy ridge was easily picked out with a finely textured damp sponge and the richer darker area at the top of the picture was achieved by mixing a tiny quantity of Indian red into the blue.

It is a good idea to mix a fairly strong colour for the sky because if you start with it, as I often do, it is necessary to compensate for the bright white of the rest of the surface. The sky will appear less vivid as colour is applied elsewhere. It is possible to re-tint the sky at a later stage and I find it more satisfactory to apply this other wash, when necessary, with the painting turned upside down on the easel, working from the horizon. Do not forget to dab and soften the bottom edge of a wash or a hard edge will show persistently through subsequent painting.

Water and sky are related in terms of colour. It is therefore important to incorporate the blue of the sky into the water. In order to get some initial feeling of unity in the picture I worked broadly overall with washes of colour. This is often a good time to erase heavier pencil lines, particularly along the horizon – although it is possible, miraculously, to remove extraneous pencil that is under a wash of colour, but this is best avoided.

Masking fluid was used to pick out light toned branches. It was also applied over light washes of colour that had been allowed to dry in anticipation of a darker wash eventually covering it. Masking fluid is certainly a most useful item; its main drawback is its yellow tint, which while it is present in the painting can affect the decisions made about colour elsewhere.

Good equipment is vital to success. A Number 12 sable is a very expensive item but will last a lifetime and give reliable service. A poor-quality brush will probably shed hairs at critical moments. If a hair does stick to your work wait until the paint has dried and gently rub it off. With luck it will come away cleanly. I use a small range of brush sizes apart from the Number 12, generally working from a Number 5 to a Number 3 or sometimes finer. Artists’ quality paints, while expensive, are long lasting because the pigment is so strong. However, some makes of Prussian blue and ultramarine contain rather coarse granules of paint and I avoid them for the sky.

Watercolour board is a great boon and allows for spontaneity, since it needs no preparation. It is also an easy support to use in the field since it is stiff and light. In smallish pieces it does not need to be fastened to a drawing board which, of course, means one less thing to carry. Naturally, it has different properties from stretched hand-made paper, one being that it dries much more quickly. This may not suit the tastes of a wet-on-wet watercolourist, but in my work it is usually only large areas of sky or water that may require a wetter approach, and these have to be resolved in the main with speed because of the drying characteristics of the board. I use a hot-pressed surface because I prefer a smoother, more uniform application of colour and find the ‘not’ surface unsympathetic to the fine lines and sharp edges of architectural subject matter.

A last point worth mentioning is the tendency for colour fastness to increase with time. This means that any changes or corrections should be washed out or over as soon as possible.  Leaving an accidental or unwanted mark overnight may make it impossible to erase.

My technique could be best described as ‘dry’. At this stage small areas of the painting have been built up with details slowly emerging, drawn in with the paint brush. Every mark counts; dabs become leaves on trees and undergrowth; sketchy lines become twigs and branches. The masking fluid has served its purpose and has been removed with a soft clean rubber. I used my fingers to make ‘bushes’ and a dry coarse sponge rubbed lightly in paint to add interest to distant tree tops.

The temptation is to finish off each part of the painting at the risk of its overall effect, particularly with a structure like this, which falls easily into well-defined areas. I had, however, practically finished the castle:  it is the subject of the painting and the degree of detail necessary dictated the final appearance of the rest of the picture. The left hand river bank took shape more rapidly than the right because I had to make a further trip to the bridge to study buildings almost hidden by trees and this visit was delayed by poor weather.

As I worked over the surface of the painting I added colour to the river, building up the reflections.  Generally, water will lie flatter if the marks run horizontally, but some realistic effects can be achieved by putting colour on in strokes across the surface, then softening them with clean water applied in vertical strokes over the top.  Obviously, on very still water the reflections are going to be clearer than on a moving or windswept surface.

Details of branches or indeed anything else that needs clarifying can be picked out with Aquarelle crayons. These are a most useful addition to paint and can produce an easily controllable fine line. The crayon marks will stand a lightly applied wash without smearing but will bleed colour if worked on with a brush. The painting needed detail and strong contrasts in the foreground to create effective distance between it and the castle. Because the two river banks form distinctly separate areas I also had to be sure that the larger left-hand side did not predominate.  I counterbalanced its heaviness by darkening the shadows on the right-hand side. The sky had lost some of its depth because of the considerable tonal range in the rest of the picture. I therefore re-emphasised the effect by adding a wash of darker blue to the sky right at the top of the painting.

When busy with final adjustments it can be enormously helpful if you place a ‘frame’ around the painting. I tend to dab colour experimentally on the waste card at the side and these marks become very distracting. An old mount cut in half through diagonally opposite corners, so that the two pieces can be adjusted to fit around work of any size, is ideal, or just some broad strips of white paper fastened on with bulldog clips. Seeing work afresh is always helpful. Taking it into another room and viewing it in a different context can be revealing, as can looking at it from a greater distance. There are almost always small items to put right: a tree looks too stiff because I had not paid sufficient attention to middle tones on the trunk, and the golden willow trees need branches picked out in stronger colour because they are invisible at any distance.  At this stage, the painter has to become the viewer.

Knowing when to stop can be a problem. For me the point is reached when I realise that if I persist with a certain course of action I will have to repaint the rest of the picture to match.  Better to paint another!

The completed painting measures 24½” x 31” and was largely produced in the studio. Constable’s method was to study out of doors but compose in the studio and my working method is a variant of that approach. This particular painting has provided the opportunity to explore new subject matter in a direct way. Next time, I shall aim to catch the castle and river unawares and explore its potential for poetry:  an early morning mist has a magical effect!

Warwick Castle. Watercolour 24½” x 31”.