Hints and Tips
Choosing paints
Watercolour paints
Cotman vs Professional Artists paints
Winsor & Newton Professional Paints
When one starts to paint, they do not always realise the difference between paints and pigments. For years I have used Winsor and Newton Cotman Watercolour paints. It was not until I signed on to a Botanical Painting course that the difference was explained to me.
Cotman is the range of student grade watercolours from Winsor & Newton. The professional grade is called the Professional Artists' Watercolour.
Watercolour paint is made of pigment and binder. The amount of pigment controls the intensity of the colours. Binder holds the pigment (typically power) together. The more binder there are, the less intense or saturated the colour is. You can make a colour less intense by mixing or adding water, but you can't make a colour more intense than it is initially. So what you want is to start out with an intense colour.
You will find that the Cotman sets of watercolours are cheaper than the Artists’ Watercolour, this is because of the cost of the pigments. In the long run it is a false economy.
Pans vs Tubes
Pans contained hardened paint, which does not dissolve as easily as paint from tubes. Paint from tubes, even when dry will dissolve more quickly than pans. Pans may be more suitable as you can use them straight away.
You can make your own pans, by squirting tube paint into pans. Empty pans are available from suppliers such as Jackson’s Art.
Properties of Paint
All watercolour paints are labelled with an ASTM International rating. This is a rating given by the American Standards for Testing and Manufacture. Paints are labelled with properties of permanence, light fastness, whether they are transparent, semi-transparent or opaque, the Series ( related to cost), colour index name and the pigments used. Tubes are labelled on the back and pans on the side. ( a solid square means the paint is opaque.) However if there is any doubt look up the paint on the manufacturer’s colour chart and click on the colour. https://uk.winsornewton.com/collections/professional-watercolour
In addition, there are a number of colours described as fugitive, i.e. Opera Rose, which will fade, change colour or even disappear. Their use is not recommended, think of them as temporary.
As a summary:
Permanence AA to C Permanent to Fugitive
Light Fastness I to IV Good to poor
Colour Index Name Cobalt blue known as permanent blue - PB28
Chemical Series 1 to 5 Cheap to expensive
Granulating/staining marked with a “G”
Choosing paper
Paper comes in many forms, depending on the use. It varies in smoothness, absorbency, colour, texture and weight.
Paper weight is measured in grams per square meter (gsm) or pounds (lbs), refers to the weight of a ream (500 sheets) of paper of a specific size, indicating its thickness and durability. Good quality office paper used for normal printing is approx. 90g.m-2, smooth paper card is 140g.m-2, cartridge paper is 100-200g.m-2 and board weight paper suitable for art prints is 300g.m-2.
For general sketching with pencils or pen and ink, cartridge paper can be used. This is too absorbent for use with watercolours.
Bristol board is a very smooth, bright white, non coated, machine finished card, 250g.m-2. It is so named after the 4th Earl of Bristol, a prolific art collector. This is suitable for work in coloured pencils, pen and ink and light watercolour washes.
Watercolour papers are specialised papers and come in three main forms, hot pressed (HP), cold pressed (NOT) and rough.
Hot Pressed is the smoothest watercolour paper and is great for artists wishing to paint their subjects in fine detail. It gives a nice flat finish which is good for reproduction.
Cold Pressed paper has a medium textured surface suitable for beginners as it is compatible with a variety of techniques and applications.
Rough is the most textured watercolour paper. The deep pits in the paper are brilliant if you want to get the most out of the granulation of your watercolour paints and suitable for those with a loose watercolour painting style.
In addition to the roughness of the paper, watercolour paper comes in different weights, different compositions, different sizing and colours. Heavy papers, i.e. 300g.m-2, will withstand heavy washes and rubbing out. It should not need stretching as with lighter papers. They are made from two materials, cotton or wood pulp. Cotton paper is considered to be the best professional quality giving stability and long lasting. Wood pulp paper is made from chemically treated pulp where the lignin has been removed. It is suitable for amateurs and beginners.
The paper comes in bright white, white and cream, depending on the manufacturer. It comes in blocks, gummed pads, glued blocks and loose sheets. The advantage of gummed pads is that it retains its shape while being painted. Some papers are mould made, chlorine free, acid free and archival quality, preserving your art for years to come. Most papers are treated with sizing to reduce their absorbency. If you take a sheet off a pad, make sure you are painting on the sized side. You should be able to see the irregularities – looking at the paper at an angle.
Sizing is where the paper has been treated with something such as gelatine with the addition of alum to prevent deterioration.
Suppliers of paper are those such as Jacksons Art, who give a guide on papers and Cass Art. Papers generally used are Arches, Fabriano, Saunders Waterford, St Cuthberts Mill, L’ Aquarelle Canson Heritage, Langton.
If you want further information on papers, Lizzie Harper and Diane Sutherland have both produced blogs on their experiments with papers. https://lizzieharper.co.uk/2017/05/botanical-illustration-comparing-hp-watercolour-papers-1/
https://diannesutherland.blogspot.com/2013/11/which-watercolour-paper.html