Here is a quote from one of the above articles ...lots or reading there, and info for you...and here is that quote;
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Each piece of decorated glass is placed on a mold, which determines its final form. Most of the molds are produce in ceramic and coated with a clay dust which keeps the glass from adhering to the mold and which gives a unique pebble finish to the back of each piece. Peggy designed the kilns in the early 1990's specifically for her product. When the glass and color are heated to 1600° F they fuse together and form one piece of glass, sealing and protecting the design forever. Each piece of Peggy Karr Glass undergoes a thorough cleaning and inspection before it can bear our distinctive inscription; 'PKG...."""
There you go! You can also look on E-Bay for other pieces of hers. There that was fun...LOL

Sometimes we hit, and sometimes it takes years to figure something out .... but we work as a Group from all over the world. Just a note too, several of people on here are also Glass authors on Books for Glass. So your with a Great Group! Again Welcome !!