| BOARDS AND PANELS | Man-made boards are cheaper to buy and prepare than stretched canvas; they are also easier to store and transport, and they will provide a more durable support than canvas. |
Wood panels
Wood, for centuries the traditional support for oil and tempera painting, can no longer be relied upon to be well seasoned, so it tends to split and warp. It is also heavy to transport, and is now largely superseded by economical composition boards.
Hardboard (Masonite)
Hardboard is inexpensive, strong and lightweight. It is available in two forms: tempered and untempered. The tempered variety is suitable for oil paints and primers, and it does not require sizing. For acrylic painting, however, use untempered board, which has no greasy residue. Sundeala board, grade ‘A’, is particularly recommended, as it is lightweight and its surface is slightly more porous than standard hardboard, giving a good key for size and primer.
Hardboard has one smooth and one rough side; the smooth side is the one most often used. The rough side has a texture which resembles coarse canvas, but it is only suitable for heavy impasto work, as the texture is very mechanical and over-regular.
Hardboard is prone to warping, particularly in humid climates, but this risk is reduced by priming the front, back and edges of the board. Paintings larger than 45cm (18in) square should additionally be braced with a framework of wood battening across the back (see here).
Plywood
Plywood comes in various thicknesses and has smooth surfaces. It does not crack, but it can warp. To keep the sheet stable, size and prime it on the front, back and edges. Large sheets should be battened or ‘cradled’ by gluing wooden battens to the back of the board (see here).
Chipboard
Chipboard is made from wood particles compressed into a rigid panel with resin glue. Thick panels of chipboard are a sound support as they do not crack or warp and don’t require cradling, but they are heavy to transport. Another disadvantage is that the corners and edges may crumble, and, being absorbent, they need to be well primed.
Medium-density fibreboard (MDF)
MDF is made from pressed wood fibre and is available in a wide range of thicknesses and in standard board sizes. It is a dense, heavy, but very stable material and has fine, smooth surfaces. MDF is easily cut by hand or with machine tools. Large, thin panels may need to be cradled to help keep them flat (see here).
Cardboard
Degas and Toulouse-Lautrec painted on unprimed cardboard on occasions; they used its warm brown colour as a middle tone, and produced a matt, pastellike effect on the absorbent surface. However, a finished painting must be framed under glass if it is to last. Cardboard must be sized on both sides and on the edges to prevent warping and to stop impurities in the cardboard from leaching into the paint.
Mount board
Heavy mount board, or pasteboard, is available in a range of colours and has a smooth surface suitable for painting in acrylics and gouache, particularly when thin washes and glazes are applied. It is also used for pen-and-ink drawing. Always choose conservation board for work that is intended to last, as this is guaranteed acid-free.
Watercolour board
Watercolour board consists of a solid core faced with good-quality watercolour paper. The board provides extra strength and stability, and dispenses with the need for stretching paper prior to painting. Check that the core of the board, as well as the paper, is acid-free. Watercolour boards also perform well with pastel and charcoal.
Pastel board
Pastel paper mounted on board is available in a range of sizes, colours and finishes, from soft velour to a high-tooth, abrasive surface.
Canvas boards and panels
Commercially prepared canvas boards and panels consist of acrylic-primed cotton canvas mounted on rigid board. They come in a range of standard sizes and surface textures, and are a good choice for beginners. Because they are compact and lightweight, they are ideal for painting outdoors. Cheaper-quality canvas boards with an imitation canvas surface have an unsympathetic, mechanical texture and a rather slippery surface priming, and the backing board is prone to warping.
Marouflaging board
Many artists prepare their own canvas boards by covering boards with canvas or muslin – a method known as marouflaging. Fabric glued to board provides a surface which combines the unique feel of working on canvas with the greater stability of a firm surface which is not prone to movement under atmospheric changes. Any natural fabric can be used, such as worn linen, cotton sheets or tablecloths, unbleached calico, butter muslin or canvas offcuts.
Method
Check that the board is cut square and true. Dress the edges and lightly sand the smooth side to provide a key for the glue. Brush away all sawdust. Lay the board over the fabric, then cut the fabric to size, allowing a 50mm (2in) overlap all round (1).
With a household paint brush, apply size to the face and edges of the board (2). Smooth the fabric over the board with an equal overlap all round (3). Ensure that the warp and weft threads lie straight and parallel with the edges, as any distortion in the weave will show in the finished picture and be visibly distracting.
Apply more size to the cloth, brushing from the centre outwards and smoothing out any creases or air bubbles. When the size has dried, turn the board over and trim across the corners (4).
Size a margin around the edge of the reverse of the board, wide enough to stick down the overlapped cloth, which should not be pulled too tight as it may cause the board to warp. Smooth down the flaps of material and fold the corners over neatly (5). Add a final coat of glue over the reverse side to prevent warping. Leave to dry flat overnight before priming.
Keying hardboard
Before painting on the smooth side of hardboard, lightly sand the surface to provide a key for the application of primer.
Preparing a panel
To save time, an artist will periodically prepare a batch of panels at once, all cut from one sheet of board. For example, from a sheet of hardboard measuring 120 × 240cm (4 × 8ft) you can cut thirty-two 30.5 × 30.5cm (12 × 12in) panels, or thirty-eight 25.5 × 30.5cm (10 × 12in) panels. Most timber yards cut board for a small fee, or you can cut it yourself.
Cutting panels
Mark out the sheet with a rule and pencil, making sure all the corners are square, and saw along these lines. Now ‘dress’ the edges of each panel with a sanding block to remove any burrs from the saw cuts. To provide a key for the size or priming coat, lightly sand the surface of each panel. Always use a light touch; too much downward pressure may create depressions in the board.
Cradling boards
Cut two battens 50mm (2in) shorter than the width of the board. Chamfer the ends and then secure the battens to the back of the board, using wood glue for man-made boards, or woodscrews for solid wood or thicker boards.
Gesso panels
Gesso