Complete Artist’s Manual: The Definitive Guide to Materials and Techniques for Painting and Drawing

SEE ALSO

PRIMING

Preparation

Paper must always be sized before oil paint is applied in order to prevent the oil binder being absorbed and leaving the paint film underbound. The paper may be sized with rabbit-skin glue, PVA glue or acrylic matt medium, or primed with acrylic primer. Sizing is not necessary for acrylic paints.

Types of paper

Watercolour paper

Heavy, rough-surfaced watercolour paper or handmade Indian paper can be used as a support for oil and acrylic painting. The paper’s texture shows to advantage when the colour is applied in thin washes. For extra strength, the paper can be mounted on to hardboard.

Oil-painting paper

Sheets of paper, textured to resemble canvas and primed ready for oil painting, are available in fine or coarse grades. Cheaper-grade oil-sketching paper comes in pad and block form. This is convenient for sketching out of doors and is economical for practice work, but you may find that the surface is greasy and unpleasant to work on, like that of the cheaper painting boards.

Acrylic sketching paper

This comes in the form of spiral-bound pads of embossed, acrylic primed paper, which are very convenient for small paintings and sketches.

Paper for oil painting

Indian paper and canvas-texture paper

Size this with rabbit-skin glue, PVA glue or acrylic matt medium, or coat with acrylic primer.

Painting on paper

Paper is an excellent and economical support for painting. It will accept most media, as long as you follow the rules of preparation. This painting is in acrylics, worked directly onto a good-quality, heavy-weight watercolour paper. A toned wash of thinned acrylic was applied first, to tone down the white surface and to act as an extra size for the support.

Dennis Mathew Rooney

Haunt of Ancient Peace

Acrylic on watercolour paper

38 × 53cm (15 × 21 ¼in)

SEE ALSO

SIZING FOR OILS

WATERCOLOUR PAPERS

OIL TECHNIQUES

ACRYLIC TECHNIQUES

Function of size

Size seals the pores between the fibres of the support, making it less absorbent. This prevents the oil binder in the priming and paint layers from sinking into the support, leaving the paint film underbound and liable to sinking, flaking and cracking.

Rabbit-skin glue

Rabbit-skin glue has traditionally been used for sizing oil-painting supports, since it has good adhesive strength. It comes in the form of granules, and is available in most art-supply shops. The glue size is made by mixing dry glue with water and gently heating it – but be warned that it smells unpleasant!

Preparing size

The ingredients should be carefully measured to produce the required strength (see here). If the size is too strong, it forms a brittle layer which could cause the primer and the painting to peel and crack; too dilute a size will produce a weak film which allows oil from the upper layers to sink into the canvas.

Place the dry granules into the top part of a double boiler. Add the water and leave for about two hours to swell. Heat the resulting solution gently in the double boiler until it has melted, stirring until all the granules have completely dissolved, and never allowing the size to boil – this will destroy much of its sizing qualities. If you don’t have the use of a double boiler, you can heat the glue in a bowl standing in a pan of water (as shown in the illustration, right).

Set aside the glue for a couple of hours, to cool and form a jelly. Keep the container covered to prevent any loss of water through evaporation, and to protect from dust and flies. Test the strength of the glue with a finger – the surface should be rubbery, yet just soft enough to split. The split formed should be irregular; if it is smooth and clean, the size is too strong. If this is the case, just rewarm it, add water, and allow it to reset. If the size has not set, you can stir in up to 10g (¼oz) of glue and then leave to soak for 12 hours.

Preparing size in advance

If you are mixing up a batch for later use, it is useful to note that glue size can be kept in a refrigerator for up to a week before starting to decompose.

Applying size

Rabbit-skin glue is a strong adhesive and must be used thinly, or it will crack. One thin coat is sufficient to size a canvas; too thick a layer forms a continuous, level film on the surface, and prevents the subsequent priming layer from bonding with the canvas. Gently reheat the size until it is just lukewarm and almost jelly-like in consistency. Apply it to the canvas in a thin layer, working quickly before the size begins to dry. Start from the edge, and brush in one direction only – do not make a back-and-forth motion with the brush, as too much size will be applied. Size the back flaps and edges of the support as well as the front. Leave to dry in a dust-free place for about 12 hours before applying primer.

Temperature

Size may be applied hot to panels and boards, but on canvas it must be applied lukewarm. If too hot, it will soak through and glue the canvas to the stretcher and you will need to prise it free with a palette knife. Hot glue size may also cause fabric to over-tighten.

Sizing boards and panels

For boards and panels, use the slightly stronger solution described on the opposite page. Thin boards should also be sized on the reverse and edges, to prevent warping. Leave to dry for 12 hours, then sand lightly.

Rabbit-skin glue

This is the time-honoured size for rendering canvas impervious. Available in granule form, it is dissolved in hot water.

Recipes for glue size

These measurements are a good starting guide, although you may wish to vary them slightly.

For sizing canvas:

You need 55g (2oz) – two rounded tablespoons – glue to 1.1 litres (2 pints) water. (Alternatively, use 1 part by volume of glue to 13 parts water.)

For rigid panels:

Use a stronger solution of 85g (3oz) glue to 1.1 litres (2 pints) water. This recipe will make enough size to cover a support measuring about 120 × 180cm (4 × 6ft).

Improvised double boiler

An effective substitute can be made from a bowl or clean tin can heated in a pan of water.

Sizing implements

Brush size in one direction only

The best brush for sizing is a flat hog varnishing brush, with a good width and long bristles. Decorators’ brushes can be used, but poor-quality ones may shed hairs. Some artists use a natural sponge, which gives more control; gently squeeze out more glue when you feel the surface going dry. It can also be used to mop up any excess.

Unprimed supports

The warm brown tone of surfaces such as hardboard, plywood, cardboard and linen canvas provides a middle tone which can be incorporated into the painting. To make them suitable for painting on, while maintaining their colour and texture, seal them with a coat of dilute glue size (for oils) or acrylic medium (for all media). Here, Ken Howard uses very thin, turpentine-diluted paint, so that the canvas colour shows through. This gives a marvellous impression of reflected light on the model’s back.

Ken Howard

Homage to Lautrec

Oil on unprimed canvas

40 × 30cm (16 × 12in)

Alternative glue size

A modern alternative to traditional glue size is carboxymethyl/cellulose (CMC). This expands and contracts at the same rate as the canvas, greatly reducing the risk of cracking. It is also easier to use: just dissolve the granules in either warm or cold water (using an 8 per cent solution by volume), leave to swell and apply with a stiff brush. There is no heating involved – and no smell.

SEE ALSO

CANVAS

BOARDS AND PANELS

PRIMING

FAT-OVER-LEAN

UNDERPAINTING

Choosing primer

There are various types of primer, each with its different characteristics. It is important to choose the right one for your needs, as it affects the way paint is ‘pulled’ from the brush, and its finished appearance. For example, if you like to work on a smooth surface, you will require a different ground to someone who prefers a slightly textured, dryish surface that gives the paint a matt, chalky appearance.

In addition, it is vital that you select the right type of primer for your chosen support. Canvas expands and contracts, and thus requires a flexible ground; therefore an inflexible gesso ground is not suitable.

The ground should be absorbent enough to provide a key for the paint, but not so absorbent that it sucks oil from it – a common cause of sinking (the appearance of dull patches of paint across the canvas).

Oil primer

The traditional, and best, primer for oil painting, particularly on stretched canvas, is oil-based lead-white primer. This is flexible, stretching and contracting with the canvas on changes in temperature and humidity. It dries to form a durable base, which will not absorb too much oil from the paint.

Applying oil primer

Lead-white primer is quite stiff, and should be let down slightly with turpentine so that it can be brushed out easily. Apply an even coat as thinly as possible, brushing it in well (1). Finish off with a long smoothing stroke in line with the weave of the cloth (2). You should leave this first coat to dry for two days before applying a second coat.

The primed canvas should either be used while touch-dry (within a week or two) or be left to cure for four to six months before use. If paint is applied between these times, the primer sucks oil from the paint, leaving it underbound and with insufficient adhesion to the support.

Yellowing

The linseed oil in which lead white is ground turns the priming coat yellow if the primed support is stored away from the light for any length of time. The whiteness is restored upon exposure to sunlight.

Alkyd primer

This is a valid alternative to oil primer, as it is flexible, non-yellowing and fast-drying; each coat can be overpainted after 24 hours. Dilute alkyd primer with white (mineral) spirit to the required consistency.

Acrylic primer

Acrylic primer is flexible, durable, water-thinnable, fast-drying and inexpensive. It can be used to prime canvas, board, paper and other surfaces, and can be applied directly to the support without the need of an isolating layer of size. It dries in a few hours.

Acrylic primer is the ideal surface for acrylic paints, providing a bright undercoat which brings out the vividness of the colours and gives added luminosity to thin washes. It can also be used with oil paints on rigid supports, but this is not recommended for canvas painting, except in a thin layer: acrylic is more flexible than oil, and the different tensions may eventually lead to cracking of the paint surface.

Acrylic primer is often referred to as acrylic gesso, a confusing term as it is not a gesso at all; traditional gesso is prepared with animal glue and chalk, and is very absorbent.

Applying acrylic primer

Work from the edges and apply the primer quickly in sections. Use a large brush or a paint roller, and keep the working edge moving, as acrylic primer dries quickly. Leave to dry for a few hours. The second coat should be applied at right angles to the first.

When priming board, you can apply as many as five coats for greater whiteness and opacity. For a really smooth finish, thin the last coat with a little water. For a textured finish, impress a piece of canvas (or any textured fabric) into the final coat of primer while it is still damp. Pull it away, then let the panel dry.

Checking primers

Commercially produced primers may become hard if kept on the shelf for too long, so it is wise to shake a tin before buying it to make sure that the contents are still liquid.

Applying primer:

• Apply it in several thin coats – a thin coat is pliable while a thick coat is likely to crack and may even flake off the support.

• Cover the entire surface evenly. Don’t go back over brushstrokes.

• Make sure that each coat is touch-dry before any subsequent coat is applied, and also before starting to paint.

(1) Applying a thin, even coat

(2) Finishing off

Acrylic over glue

Never use acrylic primer over animal-glue size, as it will prevent the paint from adhering properly to the support.

Paint rollers

It is a good idea to use a paint roller to apply acrylic primer. A roller keeps the paint moving and delivers an even coat; for small supports, use a small radiator roller.

Working sequence

Work in sections; leave primer to dry between coats; apply subsequent coats at right angles.

Emulsion paint

An economical primer, often used by students, is ordinary matt household paint, which provides a sympathetic, semi-absorbent ground. However, household paint should only be used on rigid supports, and not on stretched canvas. Use only good-quality paint; cheap emulsions have a limited life span.

Using primer creatively

The lovely, matt, airy quality of Fred Cuming’s paint is due in part to the ground he works on. After many years of painting, Cuming still finds the best primer is a good-quality, matt, white undercoat. When the primer is thoroughly dry, he applies a thin layer of linseed oil to the surface and wipes it off immediately, leaving just a trace of oil. When this is dry – after two weeks – the resulting surface provides a sound key for the paint, and prevents it sinking.

Fred Cuming

Bathers – Cap Ferrett

Oil on panel

60 × 50cm (24 × 20in)

Brian Sinfield Gallery, Burford

Textured finish

For a textured finish, lay and then press a piece of textured material, such as an old piece of sacking, into the final primer coat.

SEE ALSO

CANVAS

BOARDS AND PANELS

SIZING FOR OILS

TONED GROUNDS

OIL PAINTS

FAT-OVER-LEAN

TEMPERA

ACRYLIC PAINTS

Egg-oil emulsion

This general-purpose, easily made primer is suitable for canvas and board. It is ready to paint on after two days’ drying (see list of ingredients here).

Break the egg into a jar. Using the eggshell as a measure, add the same volume of refined linseed oil and twice the volume of cold water. Screw the lid on the jar and shake vigorously until an emulsion is formed. Grind a little emulsion with titanium white pigment until it forms a stiff white paste; add the rest of the emulsion to bring the mixture to the consistency of double cream. Thin the mixture to a milky consistency with lukewarm glue size mixed 1 part to 12 parts cold water. Brush very thinly onto a sized support.

Traditional gesso

Brilliant white gesso (see ingredients here), is very smooth and porous, and is the ideal base for painting luminous colours and detail. Gesso is best applied to a rigid support prepared with glue size – it is not flexible enough for use on canvas. It is most suited to water-based paints, such as tempera, acrylics and Chroma colours.

Heat the size, mixed 1 part to 8 parts cold water, gently in a double boiler. Slowly add some warm size to the whiting and stir until it forms a thick paste. Blend without creating excess bubbles. Gradually add the rest of the size until a smooth, creamy mixture is obtained. (Keep the pot of gesso warm and covered, otherwise it will harden, the water will evaporate and the glue will become too strong.) To increase the brilliance, add powdered white pigment. Leave for a few minutes before using.

Applying gesso

Apply gesso carefully in thin layers and work quickly: if you go back over an area, streaks will develop. Dampen the brush with some water to prevent air bubbles forming on the surface. Apply the first coat of hot gesso in short, even strokes (1), keeping the working edge moving – when the gesso begins to cool, move on to an adjacent area. Apply up to six coats for a dense, white finish; add each coat at right angles to the last (2), using short back-and-forth strokes. Each coat should be completely dry before the next one is applied. Level off in one direction (3). Lightly sand between coats with fine sandpaper (4), dusting off the surface before applying the next coat.

Egg-oil ingredients

• titanium white pigment

• one egg

• linseed oil

• glue size

• water

(1) Applying the first coat

(2) Adding coats at right angles

(3) Levelling off

(4) Sanding between coats

Gesso ingredients

• 1 part Gilder’s whiting

• 1 part glue size

Sealing gesso

On an absorbent gesso surface, oil paint takes on a matt, airy quality which is pleasing but makes the paint quite difficult to handle. In addition, gesso soaks up much of the oil from subsequent paint layers, leaving them brittle and prone to cracking. To overcome this, the dry gesso surface should be partially sealed with a weak solution of glue size (about half the strength used to make the gesso).

SEE ALSO

PRIMING

ACRYLIC PRIMER

TEMPERA

ACRYLIC PAINTS

CHROMA COLOUR

COLOUR HARMONY

‘Reading’ tones and colours

A white ground can give a false ‘reading’ of tones and colours, especially in the early stages of a painting, when there is nothing to relate them to. Most colours appear darker on a white surface than when they are surrounded by other colours, and this creates a tendency to paint in too light a key. If you work on a neutral, mid-toned ground you will find it much easier to assess colours and tones correctly, and you can paint towards light or dark with equal ease.

If the colour of the ground is allowed to show through the overpainting in places, it acts as a harmonizing element, tying together the colours that are laid over it.

Choosing a ground colour

The colour chosen for a toned ground will depend on the subject, but it is normally a neutral tone somewhere between the lightest and the darkest colours in the painting. The colour should be subtle and unobtrusive, so that it does not overwhelm the colours in the overpainting. Diluted earth colours, such as Venetian red, raw sienna or burnt umber, work very well, as do soft greys and greens.

Transparent and opaque grounds

A toned ground can be either opaque or transparent. With a transparent ground (also known as imprimatura), the paint is heavily diluted and applied as a thin wash. A transparent ground allows light to reflect up through the succeeding colours, thereby retaining their luminosity, and it is used where transparent or semi-transparent colour is to be applied. Opaque toned grounds are used with opaque painting methods, where the light-reflecting qualities of a white ground are not so important.

Applying transparent grounds

Dilute the colour until it is thin, and then apply it with a large decorator’s brush or a lint-free rag. Loose, vigorous strokes give a more lively effect than a flat stain of colour. After a few minutes, you should rub the wash with a clean rag, leaving a transparent stain.

Making opaque grounds

Mix a little tube colour into the white priming or gesso before applying it (see here). Alternatively, you can mix the colour with white paint, dilute it a little, and then brush a thin layer over the priming. Never mix oil paint with an acrylic primer, or vice versa.

Drying times

A toned ground must be dry before you can paint over it. An oil ground takes a day or two to touch-dry; an acrylic ground is dry in minutes. So long as it is applied thinly, you can use acrylic paint for the toned ground and work over it with oils.

Ground colours

Diluted earth colours, such as Venetian red, raw sienna or burnt umber, are subtle and unobtrusive.

Jacqueline Rizvi

Two Apples

Watercolour and body colour on toned paper

17.5 × 22.5cm (7x 9in)

Jacqueline Rizvi rarely works on white paper. The rich, glowing effect of this simple still life is enhanced by the use of toned paper as a base for delicate washes of watercolour and body colour.

Paper production

There are three ways of producing watercolour paper: by hand; on a mould machine; and on a fourdrinier machine.

Handmade paper

The very best papers are made of 100 per cent cotton, and are usually made by skilled craftsmen. Handmade papers are lively to use, durable, and have a pleasing irregular texture. They are expensive, but worth the cost.

Mould-made paper

European mills produce watercolour paper on cylinder-mould machines. The paper fibres are formed into sheets with a random distribution, close to that of handmade papers. The paper is durable, extremely stable, and resistant to distortion under a heavy wash.

Machine-made paper

Although inexpensive to produce and to purchase, machine-made papers are less resistant to deterioration, but they may distort when wet. Some papers also have a mechanical, monotonous surface grain.

Choosing paper

Watercolour paper is an excellent surface for acrylics, pencil, ink, gouache and pastel, as well as watercolour. The character of the paper, and its surface texture, play a vital role in the finished picture. Very often it is the choice of paper that is to blame for a painting going wrong, rather than any inadequacy on the part of the artist.

Some papers are superior in quality to others, but it does not necessarily follow that an expensive paper will give you better results. The important thing is to find a paper that is sympathetic to what you want to do. For example, it is no good using an absorbent rag paper if your technique involves repeated scrubbing, lifting out and using masking fluid; the surface will soon become woolly and bruised.

Popular papers are available in local art shops. Specialist art shops stock less common and handmade or foreign papers; some are also available by mailorder direct from the mill or through distributors, who can send sample swatches, price lists and order forms.

Once you have settled on a favourite paper, it pays to buy in quantity. The bigger the order, the more you save.

Paper sizes

Sizes of papers will differ from country to country, and it is still common practice for art suppliers to describe paper in imperial sizes. The following table is a guide to imperial sizes and their metric equivalents.

Medium

22 × 17½in

(559 × 444mm)

Royal

24 × 19in

(610 × 483mm)

Double Crown

30 × 20in

(762 × 508mm)

Imperial

30½ × 22½in

(775 × 572mm)

Double Elephant

40 × 26¼ in

(1016 × 679mm)

Antiquarian

53 × 31in

(1346 × 787mm)

Experimenting with watercolour papers

Try out different textures and makes of watercolour paper until you find one which suits your painting style. As you become more knowledgeable, you will also be able to choose a paper to suit your subject.

In these examples, the artist has chosen a smooth texture for the nude study (below), which is perfectly appropriate for the tone and texture of the flesh. The winter-evening snow scene (centre) is ideally suited for a medium-texture paper which conveys the effect of misty light and captures the subtle grain of the snow. A rough-texture paper (bottom) communicates the solidity of the building and the dampness of the weather to the viewer.

Choosing watercolour papers

Choice of watercolour papers is very much a matter of personal preference; one artist’s favourite may be another artist’s poison. The chart below is intended only as a guide to a versatile selection of widely available papers. They have all been tried and tested by professional watercolour artists; however, your own assessment may be quite different.

Paper content

Apart from water, the main ingredient in making paper is cellulose fibres, derived from either cotton or woodpulp. Cotton is used for high-grade papers, woodpulp for others. Some papers contain a blend of cotton and other cellulose fibres, offering a compromise between cost and quality.

Cotton rag

The best paper is made from 100 per cent cotton. Although the term ‘rag paper’ is still used, the raw material nowadays is natural cotton linters. Rag papers are very strong, yet pliable, and withstand demanding techniques.

Woodpulp

Woodpulp produces a more economical, but less durable, paper. Confusingly, papers made of 100 per cent woodpulp are sometimes advertised as ‘woodfree’; this is a technical term meaning wood broken down by chemical means, rather than mechanical ones – it does not signify that the paper has not been made from wood. Mechanical woodpulp still contains lignin, which releases acids into the paper over a period of time, causing it to yellow and embrittle. The chemical woodpulp used in woodfree paper is processed to remove all the lignin.

Weight

The weight (thickness) of watercolour paper traditionally refers to the weight of a ream (500 sheets) of a given size, most often imperial (about 22 × 30in or 56 × 76cm). For instance, a 72lb paper is a light paper, 500 sheets of which weigh 72lb. The more accurate metric equivalent of grammes per square metre (gsm) is now common. Lighter papers (less than 300gsm/140lb) tend to buckle and wrinkle when washes are applied, and need wetting and stretching on a board before use. Heavier grades don’t need to be stretched unless you intend to flood the paper with washes.

Absorbency and sizing

All watercolour paper is internally sized to varying degrees, to control its absorbency and produce a more receptive working surface. Heavy sizing produces a hard surface with little absorption and a long drying time; this allows you to push the paint around on the surface. Colours remain brilliant, as they are not dulled by sinking into the paper. Lightly sized papers are softer and more absorbent, with a shorter drying time. Alterations are more difficult because the paint sinks into the fibres of the paper, but absorbent papers are suited to direct, expressive painting methods.

Internal sizing

Internal, or ‘engine’ sizing means that size is added to the paper at the pulp stage, and contained in the body of the paper. Internal sizing renders the paper robust and prevents colour washes cross-bleeding beneath the paper surface, even when it has been abraded.

Surface sizing

Many watercolour papers are also surface-sized, which is done by being passed through a tub of gelatin size (hence the term ‘tub-sized’). Surface sizing not only reduces the absorbency of the paper but it also produces a more luminous wash (on absorbent papers, colours tend to dry far paler than they appear as a wet wash). It also reduces the risk of fibre lift when you are removing masking material and lifting out washes of colour.

Tinted papers

Most watercolour paper is either white or off-white, in order to reflect the maximum amount of light back through the transparent washes of colour. Some manufacturers, however, specialize in a range of tinted papers, and these are often used when painting with body colour or gouache.