Part Sheets - What the heck are they?

Part sheets are a crucial part of many of my glass creations.  So, what is a part sheet?  
It is a piece of glass that has been changed by a chemical reaction (many glasses contain chemicals, and these will react with other chemicals to create different colors) or powders, enamels, decals, or frit.

Making a part sheet often takes several firings.  Some of my part sheets were made with up to 4 firings which means they took 4 days to create.  Many of the part sheets I use only take two or three firings.

Once I have the necessary part sheets, then comes the real fun - creating something with them - often in a mosaic fashion.  (Not to say creating part sheets isn't fun, it's just not the end game.)

The image below shows a dish created from part sheets in similar hues.

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