Thanks M... a shape I have seen with the mark before.
My pleasure John.....
Here are some thoughts I have on the mark and the reason it is there.
There is a long running debate regarding provenance marks on this glass, especially for importation into the US. There is one "school" that believes that the marks were for some reason applied by exporters and not manufacturers. Many of the people in this school also like to refer to the glass as Czech Deco Export and feel that it can not be identified as to makers as they all made the same stuff... Obviously I do not agree, especially with the latter portion of their thought process.
I am viewing this in reference to the importation into the US market. US regulations required that individual pieces be marked with country of origin, but did not specify the manner; acid, ink, paper label...etc... This, in comparison to the UK, which I understand only required that the carton an assortment was packed in needed to be marked as to country of origin.
If one agrees with the idea that the mark was applied by exporters, then you would have to think that the glass was shipped from the house that produced it to an exporter facility that then unpacked the glass and marked it, repacked it, and exported it.... the exceptions to this that are accepted currently are the Kralik arched mark and the Loetz oval and square marks used post WWI. These types of marks are accepted as identifiers as to production house because it is believed they were applied by the respective factories.
This type of handling by an exporter would not only be inefficient, time consuming, and incur additional and unnecessary costs, in my opinion, but would also expose them to unnecessary risks of handling the glass and repacking it.
I, on the other hand am of the belief that in most cases, the marks were likely applied by the house that produced it prior to packing the items for transit. If we look to Loetz and Kralik, as two of the larger houses at the time, it does not make sense to me that they would apply marks, but the smaller houses would let exporters bear the cost..... and it does also not seem logical to me that the exporters would not require the glass to be marked prior to packing and shipping.
There were, as with all of this, likely exceptions to how the majority of it was done.
The new Loetz book of drawings also has at least one reference to Loetz marking glass prior to export for a specific order for a retailer. That retailer was Fensterer and Rune of New York. The reference is to where the items were packed for shipment: "Ordinarily it had the goods designated as "Made In Austria or "Made In Bohemia". The orders were packed in Klastersky Myn for the dispatch to the particular branch."
What this passage seems to indicate to me is that the retailer/exporter designated how Loetz marked the items before packing and shipment to specific branches. It has never seemed all that reasonable to me that exporters unpacked - marked - repacked glass for export. In the case of Fensterer and Rune, who ordered product directly form Loetz for export, they would have had to set up a facility in Klastersky Myn to accomplish this task, and the Loetz reference material seems to indicate that Loetz did it.
In addition we see references in the West Virginia Museum of Glass Monographs for Butler Brothers, a major importer to the US, that they, for some glass products, received items packed in factory barrels. The reference is relative to assortments of glass Butler offered, indicating that an ID of one piece would lead to an ID of the assortment. In this case, it would also indicate the production houses marked items prior to packing and shipping.
My assessment of these types marks, obviously originating in the molds during production, is that in some cases companies found it easier to do this than to stamp or label items prior to packing. It would have completely eliminated a step that was costing them money to perform.
We will likely never know for sure unless some form of documentation is uncovered here in the US or elsewhere that provides at least a partial answer, but I have to follow what seems "logical" to me.