Hampton Photo Arts

With water based products, achievable results rely almost as much on the paper surface as on the quality of the colour used.  The paper is an intrinsic part of the work. 

This is also true for oil based paintings.  It is essential therefore that the artist has a range of papers at hand which are of equal quality to his/her colour. This article discusses the criteria and terminology of artists’ papers to enable you to obtain

Paper Criteria
A paper must provide a suitable surface for painting or printmaking in terms of absorbency, colour and long-term stability.  The correct degree of absorbency [sizing] allows the colour to sit on the surface and reflect the maximum amount of light.  White papers produce the brightest images, whilst coloured papers are used for opaque or juxtaposition techniques.  Long term stability comes essentially from the papers being acid-free. that quality in the choice of your papers.

Paper Terminology

Rag Content
100% rag indicates the paper is made from 100% cotton.  The reference to rag dates to the time that old rags were used in hand-made paper mills.  The cotton used in papermaking today is direct from the plant and is called cotton linters.  Woodfree paper is made from chemically processed woodpulp and produces an acid free sheet.  It is lower in cost than cotton.

Mould-Made and Hand-Made
Mould-made refers to the cylinder mould on which the paper is formed.  The fibres are arranged at random, mimicking a hand-made sheet.  This arrangement gives dimensional stability and a unique texture to mould-made papers.  Dimensional stability reduces cockling of the sheet when water is applied. 

Hand made paper has these advantages but is relatively expensive.  The deckle is the frame which forms the outer edge of the paper sheet.  Four deckle edges is an accepted term to indicate the sheet is mould made.

Sizing
Sizing is the reduction of absorbency in the sheet.  Without it colour could not be drawn across the sheet as it would blot immediately.  Most water colour papers are both ‘internally’ and ‘externally’ sized.  Internal sizing reduces the absorbency of the fibre itself by chemically bonding to it. 

External sizing is a layer of gelatine on the surface of the paper, resulting in the water colour film laying on the surface, looking brighter and allowing it to be sponged off if desired by the painter.  Gelatine gives a harder surface which also allows scraping and rubbing without damaging the paper itself.  External sizing is also known as gelatine surface sizing.
Printmaking papers are ‘soft sized’. 

A low level of size makes the paper more malleable, particularly for intaglio work and also more absorbent, pushing the ink into the fibre and assisting drying.

Buffering
Artists’ papers are buffered with an alkaline filler, eg. calcium carbonate.  A small amount is incorporated into the sheet at the pulp stage.  This buffering allows the sheet to counteract any atmospheric acidity over the long term.

Surfaces
Water colour papers are available in three different surfaces, Rough, Cold Pressed and Hot Pressed. 

Rough is the heaviest texture, embossed from the surface of the blanket between which the sheet is dried.  Not or Cold Pressed is a Rough sheet which has been cold pressed to flatten out the texture.  Hot pressed, is just that and produces a smooth sheet.  ‘Not’ water colour paper is the most popular. 

The three surfaces are relative to each other within each manufacturer’s range, ie. Rough from one brand could be smoother than Rough in another.  ‘Not’ is the most popular as it contributes a modest texture to the water colour painting.  Rough is used by water colour painters who rely more on granulation and texture to emphasize the surface.  Hot Pressed papers are used by illustrators and minaturists where a smooth finish blends with the image more comfortably.  ‘Not’ paper gives the brightest water colour paintings because its increased surface area holds more colour and therefore reflects more light.

Pastel papers tend to have a mechanical ‘grained’ surface which helps to hold the pastel or charcoal on the paper. Printmaking papers tend towards the smooth end of the scale, with the expected variation between brands of paper.

The ‘Right’ Side
The right side of the paper is the side from which you can read the watermark. However, either side can be used, it is entirely a matter of choice.

Painting on the back of a finished painting will save using a new sheet but this practice cannot be widely recommended.  A painting which is felt to be unsuccessful today may appear entirely different in the future, you could end up with two good paintings on only one sheet of paper. Paintings may also appear less bright if there is a dark painting on the back of the sheet and may not stay flat.

Weight
The weight is measured in two ways, either Imperial or Metric.  The Imperial weight is that of 500 sheets of Imperial sized [30” x 22”] paper.  A lightweight water colour paper might be 90lb.  The Metric weight is grammes per square metre [gsm].  A 90lb paper is equivalent to 190gsm.  Papers are generally referred to as heavy or light in weight.

A heavier paper is more resilient to tearing/general storage, being stronger simply because there is more interwoven fibre in a heavy sheet.  Heavier papers are preferred by many water colourists as they are able to take heavier washes without cockling.  Lightweight papers should be stretched if substantial amounts of water are to be used. 

Cockling is the wrinkling of the sheet when substantial amounts of water are used.  Heavier sheets used in printmaking should be soaked long enough to ensure suppleness, a 300lb sheet should be submerged for at least 20 minutes.