Changes seen after varying preparative methods: Buxbaum ‘Green-tone’ recipe.

<p>Changes seen after varying preparative methods: Buxbaum ‘Green-tone’ recipe.</p

Changes observed after each calcination for the Zerr and Rubencamp ‘light recipe’ time course.

<p>Changes observed after each calcination for the Zerr and Rubencamp ‘light recipe’ time course.</p

Chromaticity diagram plotting x,y values of products from the Zerr and Rubencamp ‘medium recipe’ reduced synthesis.

<p>Chromaticity diagram plotting x,y values of products from the Zerr and Rubencamp ‘medium recipe’ reduced synthesis.</p

Proportions (expressed as ‘parts’) taken from <i>A Treatise on Colour Manufacture</i> for Ultramarine Blue Synthesis [17].

<p>Proportions (expressed as ‘parts’) taken from <i>A Treatise on Colour Manufacture</i> for Ultramarine Blue Synthesis <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050364#pone.0050364-Zerr1" target="_blank">[17]</a>.</p

Plot of T_g<i>versus</i> V_sub for Udel™ polysulphone (repeat unit ID 12) and its derivatives.

<p>Plot of T_g<i>versus</i> V_sub for Udel™ polysulphone (repeat unit ID 12) and its derivatives.</p

T_g and V_sub values for the derivatives of the commercial polymer Radel™ R, repeat unit ID 26.

<p>T_g and V_sub values for the derivatives of the commercial polymer Radel™ R, repeat unit ID 26.</p

Proportions of reactants used in recipes to examine the effect of sulphur content.

<p><i>N.B.</i>, Recipe 1 is the ‘Zerr and Rubencamp Medium Recipe’.</p

Broken pellets of (a) samples 20 and 21 and (b) samples 22 and 23.

<p>Broken pellets of (a) samples 20 and 21 and (b) samples 22 and 23.</p

UV-Vis spectra for sample 22 pellet interior (orange) and sample 23 pellet exterior (pink) after 4 hours.

<p>UV-Vis spectra for sample 22 pellet interior (orange) and sample 23 pellet exterior (pink) after 4 hours.</p

Use of natural ultramarine (blue) and synthetic ultramarine (red) amongst paintings in the Schack-Galerie, Munich, from reference 4.

<p>Use of natural ultramarine (blue) and synthetic ultramarine (red) amongst paintings in the Schack-Galerie, Munich, from reference 4.</p