Part of the Biome/Lichen Series
Litmus paper reacts changing coulour to blue in the presence of alkaline substances or red if acidic. Litchen has been collected for use as a dye, and contains litmus and orcein, dye-compounds with the peculiar quality of being reactive to pH. It is still used in the manufacture of litmus paper. The dictionary meaning of  'litmus tes't is a test in which a single factor (such as an attitude, event, or fact) is decisive. 
This work is part of a wider series of botanical musings using colour,  exploring concepts and opinions that can be hard to pin down or measure. Metaphorically, the Litmus Test is a quick, decisive, and critical indicator - a yardstick used to gauge opinions, attitudes, or the future success of a broader concept or person. But we are in a  time of rapidly shifting opinions as what we thought to be true is challenged.  Age causes some of these shifts, polarising views just when it should open them up A political or chemical spectrum?
Overlays of red & blue glazes