Colour Number: 19
Pigment Details: Sulphur containing Sodium Aluminosilicate / Colour Index Pigment Blue 29 (C.I. PB29)
Ultramarine Blue Professional Watercolour is prepared using the synthetic mineral pigment based on the three-dimensional aluminosilicate lattice with a sodalite structure containing entrapped sodium ions and ionic sulphur groups (from “Pigment Compendium”, page 381). The pigment has been selected for its purity, light fastness and intense red shade blue hue, making it ideal for use in A J Ludlow’s Professional watercolour range.
C.I. pigment blue 29 can refer to either the natural mineral, Lapis Lazuli or the synthetic form, which is sometimes referred to as French Ultramarine, after Jean-Baptiste Guimet the French industrial chemist who in 1828 was awarded a prize for a process for making synthetic ultramarine blue. In both compounds the chromophore (or colour centre) is the polysulphide groups (which gives the mineral its blue colour), which explains why the pigment’s colour changes from blue to grey (the normal colour of the sodalite structure), accompanied by the smell of rotten eggs (caused by the liberation of toxic hydrogen sulphide (H2S) gas), when treated with mildly acidic liquids (for example lemon juice).
When the blue pigment derived from the semi-precious blue stone, lapis lazuli was first introduced into Europe in the 15th Century, where it came from and how it was produced was shrouded in mystery and the pigment was known only to have come from “beyond the sea”, hence it became known as oltramarino by the medieval Italians (at the time, the name also referred to a number of other imported goods), as most of the pigmented lapis lazuli used in both western and eastern art came from the mines in Afghanistan (Finlay 2002, page 313). It is interesting to note that other similar synthetic pigments based on the same aluminosilicate-sodalite structure are also referred to as ultramarine (for example, Ultramarine Pink), but are no longer thought of as coming from “beyond the sea”.
Being a semi-precious stone, the pigment derived from lapis lazuli is expensive and now, frequently derived from mineral deposits containing high levels of silicate, which if not removed will dilute the blue lazurite, causing the pigment's hue to be less intense and dull. Synthetic ultramarine on the other hand is a more vivid blue, since the particles are smaller and more uniform, making this pigment the best choice for Ultramarine Blue in A J Ludlow’s Professional watercolour range.
The Ultramarine Blue’s red shade allows this Professional watercolour to be used on the artist’s pallet as a warm primary blue. The watercolour’s tendency to granulate and high colour strength can be used to full effect when painting wet-in-wet or in dilute washes.
Eastaugh N, Chaplin T, Siddall R, Walsh V, “Pigment Compendium: A Dictionary and Optical Microscopy of Historic Pigments”, Routledge, Abingdon 2013
Finlay V, “Colour: Travels Through the Paintbox”, Sceptre, London, 2002
|Brand||A J Ludlow|
This ultramarine is a paint I would definitely buy again. The creamy texture of the undiluted paint is so easy to use straight from the bottle. I use a lot of greys mixed from ultramarine and raw sienna and am delighted with the outcome . The colour is beautifully intense ,drying to the same richness as when wet.
Ultramarine Professional Colou
I have painted monochrome watercolours for many years, ultramarine in particular and am very surprised by the high quality of this product. Since purchasing the paint I have produced two portraits and have found the colour very flexible. It is very intense when applied with little water and easily diluted to produce a fantastic range of light and shade when used wet in wet. I am really pleased to have been introduced to the range of Ludlow colours.