Relief engraving of text

I found part of my answer but came across a gottcha. I am working to make dials for watches. When i do line engraving I have to horizontal flip the image. I decided I wanted to do a relief engraving in brass (prior work was in anodized aluminum where I was engraving the text will fill). In this case I made the OD and the text the same layer and fhen did fill engrave (image was already flipped from doing the alumnum dial). Low and behold the image is flipped! it appears that if I do relief engraving that I do not flip the image but if I do line with filled text I do. Can someone clear up what is going on?