flashed glass
Flashed glass, or flash glass, is a type of glass{{Cite book|url=https://archive.org/details/artoftable00suza|url-access=registration|page=[https://archive.org/details/artoftable00suza/page/277 277]|quote=Flash glass.|title=The Art of the Table: A Complete Guide to Table Setting, Table Manners, and Tableware|last=Drachenfels|first=Suzanne Von|date=2000-11-08|publisher=Simon and Schuster|isbn=9780684847320|language=en}} created by coating a colorless gather of glass with one{{Cite web|url=http://www.patternglass.com/FlashCaseStain/FlashCaseStain.htm|title=Flashed? Cased? Stained? Glass decor|website=www.patternglass.com|access-date=2017-07-03|url-status=live|archive-url=https://web.archive.org/web/20170425170819/http://www.patternglass.com/FlashCaseStain/FlashCaseStain.htm|archive-date=2017-04-25}}{{Cite book|url=https://books.google.com/books?id=-bx9CAAAQBAJ&q=Flashed+glass+-wikipedia.org&pg=SA4-PA12|title=Schott Guide to Glass|last=Pfaender|first=H. G.|date=2012-12-06|publisher=Springer Science & Business Media|isbn=9789401105170|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145858/https://books.google.com/books?id=-bx9CAAAQBAJ&pg=SA4-PA12&dq=Flashed+glass+-wikipedia.org&hl=en&sa=X&ved=0ahUKEwiBlICW7-3UAhVC8WMKHR88CFQ4ChDoAQg9MAU#v=onepage&q=Flashed%20glass%20-wikipedia.org&f=false|archive-date=2018-01-18}}{{Cite book|url=https://books.google.com/books?id=trB5GH-aCPYC&q=Flashed+glass+colors&pg=PA4|title=Glass Etching: 46 Full-size Patterns with Complete Instructions|last1=Capp|first1=Robert A.|last2=Bush|first2=Robert G.|date=1984|publisher=Courier Corporation|isbn=9780486245782|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145859/https://books.google.com/books?id=trB5GH-aCPYC&pg=PA4&dq=Flashed+glass+colors&hl=en&sa=X&ved=0ahUKEwitgKWbqO7UAhXLzlQKHTG-Bx44ChDoAQgvMAI#v=onepage&q=Flashed%20glass%20colors&f=false|archive-date=2018-01-18}} or more thin layers of colored glass.{{Cite book|url=https://books.google.com/books?id=zP6bgkUWCTsC&q=Flashed+glass+-wikipedia.org&pg=PA220|title=Geomaterials in Cultural Heritage|last1=Maggetti|first1=Marino|last2=Messiga|first2=Bruno|date=2006|publisher=Geological Society of London|isbn=9781862391956|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145858/https://books.google.com/books?id=zP6bgkUWCTsC&pg=PA220&dq=Flashed+glass+-wikipedia.org&hl=en&sa=X&ved=0ahUKEwjP0rPD7O3UAhVBTWMKHSAgDR8Q6AEIQjAE#v=onepage&q=Flashed%20glass%20-wikipedia.org&f=false|archive-date=2018-01-18}} This is done by placing a piece of melted glass of one color into another piece of melted glass of a different color and then blowing the glass.{{Cite book|url=https://books.google.com/books?id=IwI-AAAAIAAJ&q=Flashed+glass+made+by&pg=PA163|title=Discovery - A Popular Journal of Knowledge, New Series, Vol. II, January to December 1939|publisher=CUP Archive|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145858/https://books.google.com/books?id=IwI-AAAAIAAJ&pg=PA163&dq=Flashed+glass+made+by&hl=en&sa=X&ved=0ahUKEwjV8bbe8O3UAhUmjlQKHYi6CT8Q6AEIMzAD#v=onepage&q=Flashed%20glass%20made%20by&f=false|archive-date=2018-01-18}}
As well as its use for glass vessels, it has been very widely used in making stained glass since medieval times, often in combination with "pot metal glass", made by colouring molten glass, giving colour all through the sheet.
The colored glass can be partly or completely etched away (through exposure to acid or via sandblasting),{{Cite book|url=https://books.google.com/books?id=4tMKnALW4Y0C&q=flashed+glass&pg=PA46|title=Strangest Genius: The Stained Glass of Harry Clarke|last1=Costigan|first1=Lucy|last2=Cullen|first2=Michael|date=2010|publisher=The History Press Ireland|isbn=9781845889715|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145859/https://books.google.com/books?id=4tMKnALW4Y0C&pg=PA46&dq=flashed+glass&hl=en&sa=X&ved=0ahUKEwiIy-enou7WAhVDxFQKHd0-DRoQ6AEIVTAI#v=onepage&q=flashed%20glass&f=false|archive-date=2018-01-18}} resulting in colorless spots where the colored glass has been removed.
Flashed glass can be made from various colors of glass.{{Cite book|url=https://books.google.com/books?id=uDlAAQAAMAAJ&q=flashed+glass+history&pg=PA22|title=A History of English Glass-painting: With Some Remarks Upon the Swiss Glass Miniatures of the Sixteenth and Seventeenth Centuries|last=Drake|first=Maurice|date=1913|publisher=McBride|language=en|url-status=live|archive-url=https://web.archive.org/web/20180118145859/https://books.google.com/books?id=uDlAAQAAMAAJ&pg=PA22&dq=flashed+glass+history&hl=en&sa=X&ved=0ahUKEwik8uPQo-7WAhXKhlQKHXo7ASEQ6AEILTAB#v=onepage&q=flashed%20glass%20history&f=false|archive-date=2018-01-18}} A finished piece of flashed glass appears translucent.