Sample of screen-printed spun rayon, afwillite 8.45 pattern, green, blue and yellow colourway, dress fabric, designed by S. M. Slade, manufactured by British Celanese, England. The pattern is based on Helen Megaw's electron-density contour map of afwillite. She explained that the 'peaks' with six or seven contours are calcium atoms, those with five contours are silicon, and the others are hydroxyl and water. Five yard length. Part of a collection of 83 samples designed for the 1951 Festival of Britain, based on X-ray crystallographic pattern.