If you are new to stained glass creation, you may be wondering what the difference is between “cathedral” and “opalescent” glass. In this video I explain the two terms, and also show how you can use this difference to your advantage when working with neutral colours of black, white and grey in stained glass.
To take a closer look at examples of variations in glass in different lighting states, check out the different photographs of my Postcard from Saturn piece. It was made from Spectrum Black/White/Clear Baroque, and surrounded by black solid opalescent glass.
Although the term “opal” often refers to white glass, as you can see the black glass in the link above is also called “opalescent”, which in this case means it is opaque or non-translucent (you can’t see through it). The terms are used interchangeably. It can be a little confusing at first, but generally speaking “opal” or “opalescent” means it has some colour in it, which you can’t see thorough 100%. “cathedral” may have colour, but it is easy to see through, like tinted glasses. Also, don’t get the word “opal” confused with the glittery opal stone. That kind of rainbow shine produced by an opal gem is actually called “iridescent” in the stained glass world.
A final reminder: be sure to check your glass in a variety of hot and cool lighting states (sunshine, overcast windows and/or cool and warm lamps) to ensure that your piece will not only look good, but transform magically!