here are some examples of what I suspect you are trying:
IMG NOTICE: [NOT AN IMAGE URL, NOT RENDERED INLINE]
I actually started a thread about it to get suggestions...the comments I received in the thread were really helpful...here is a link in case it helps:
https://photography-on-the.net/forum/showthread.php?t=535580 (there are a few more shots there too)
one crutch I also used is Live View at 5x or even 10x with spot metering on the cut portion (in your case etched) of the piece and manual focus to really get sharp detail of the pattern which also seems to move the pattern on the back side of the piece so out of focus it really does not interfere with the front side. I was specifically working with colorless glassware that day (often called "crystal" in the collector world even if the piece is not true lead crystal glassware) but the concepts port over to colored glassware perfectly.
I will reiterate something from my previous thread...getting good sharp shots will reveal every minor imperfection either in the surface of the piece or within the glass itself. These are not typically visible to the eye under normal conditions. So, you will likely want to spend some time cloning out the "nastiness"...
