Terms Explained

Colour
This is the name of the colour. These are not necessarily unique to a range or medium, e.g. Cerulean Blue exists in Water Colour and Oil Colour.

Code
This code is a number that is given to each of the colours. This is mainly used as a reference by retailers and in our catalogues but it can also help you to find the right colour when buying your colour

T/O – Transparency/Opacity
Transparent colours are marked ‘T’ and semi-transparent ‘ST’. Opaque colours are marked ‘O’ and semi-opaque ‘SO’. Transparency however, is relative and the ratings are provided as a guide only. In addition, any thin film of colour will appear more transparent than a thicker one.

Permanence
The permanence of an artists’ colour is defined as ‘its durability when laid with a brush on paper or canvas, graded appropriately and displayed under a glass frame in a dry room freely exposed to ordinary daylight and an ordinary town atmosphere’.

In simpler terms, their resistance to change when exposed to light and the atmosphere. Winsor & Newton ratings take into consideration the following factors; the natural passage of time, accelerated tests for lightfastness and binder stability, combined with results from pigment manufacturers’ testing, making our permanent ratings the most stringent in the industry.
AA      – Extremely Permanent
A         – Permanent
B         – Moderately Durable
C         – Fugitive
For further information on some colours, the rating may include one or more of the following additions:
(i)         ‘A’ rated in full strength may fade in thin washes
(ii)        Cannot be relied upon to withstand damp
(iii)       Bleached by acids, acidic atmospheres
(iv)       Fluctuating colour; fades in light, recovers in dark
(v)        Should not be prepared in pale tints with Flake White, as these will fade
(vi)       ‘A’ rated with a coating of fixative

Lightfastness
Lightfastness is shown with an ASTM rating for the pigment. The ASTM abbreviation stands for the American Society for Testing and Materials. This organisation has set standards for the performance of art materials including a colour’s lightfastness. In this system I is the highest lightfastness available and V is the lowest, though both ratings I and II are considered permanent for artists’ use.

To measure lightfastness using this system, colours are reduced to a level of 40% reflectance by the addition of Titanium White, (except for water colour which relies on the white paper). This means the amount of light reflected from the colour swatch. The swatches are then tested in both sunlight and artificially accelerated conditions.
Where no ASTM rating is given for a Winsor & Newton colour, it is labeled as N/L meaning “Not Listed”, this usually indicates that the pigment or the type of range has not yet been tested by the ASTM. It does not necessarily indicate a lack of lightfastness.

In these cases we recommend that you refer to the Winsor & Newton permanence rating, which evaluates colour on many aspects including lightfastness and is used to indicate a colour’s ability to resist fading.

Pigment Codes
This column provides the chemical description of the pigments used in each colour.

Series
The Series number indicates the relative price of the colour and is determined mainly by the cost of the pigment. Series 1 is the least expensive and Series 5 is the most expensive. Where there is no series column, this indicates the price is uniform across the range.

G/St – Granulating/Staining
In water colour, colours with granulating properties are marked as ‘G’. Many artists use granulation to add visual texture to their paintings.
As a general statement, traditional pigments granulate, e.g. cobalts, earths, ultramarines and modern organic pigments do not, e.g. Winsor colours, but the table provides information for each colour.
The water colour tables also provide information on ‘staining’ colours. . These colours cannot be lifted completely with a damp sponge and are marked ‘St’. As a general rule, modern pigments (e.g. Winsor colours) are made of very fine particles which stain the paper whereas traditional colours tend to lift from paper more easily.

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