Loetz "Kaiserrot aussen blattgrün" Ausführung 83, st PN II-5989, ca. 1908

When Deb Fitzsimmons of loetz.com documented the decor Ausführung 83 recently, it was noted that there were three colors of this decor; tiefrot (deep red), blau (blue), and kaiserrot aussen blattgrün (imperial red with a leaf-green outer layer). The difference between the two red varieties is not immediately recognizable from a distance. The tiefrot examples have a single deep red glass layer encased in clear, and appear the same color whether viewed from the outside or inside of the vase. The kaiserrot aussen blattgrün examples have a nearly opaque imperial red lining over which is applied a thin layer of leaf green, encased in clear. The result is an exterior appearance that is similar to tiefrot, but with a more muted dark brownish-red color. I was only able to detect the leaf green layer by shining a bright light through the edges of the vase (see last photo). This has solved a mystery for me, which was the question of why some of these pieces appear to be lined in a different color red. By the way, there is a vase identical to this one in the Glasmuseum Passau in Germany. See further examples of both varieties on the Ausf. 83 page of Loetz.com here:
https://www.loetz.com/decors-a-z/ausfuehrungen/ausf-83