Actually in this particular size there are glass blanks available here in the US. As for the frames, I am using the Icona Bay 4 x 6 Inch Picture Frames under www.amazon.com/Icona-Bay-Horiz…
. I like them because they look good are good quality and the beveled glass fits them nicely. They are simple but they do not distract from the engraving, because I want the engraving to be the star, so to speak.
As for other sizes either I create the frames or have them made if I want to use beveled glass.
I hope this answers your question.