This is a portion of Techsign shop drawing, with detail acquired from site survey.
We soon arrived at a means to go with, and it presented 2 alternatives. Interior parts of the graphics, technically referred to as counters (like insides of English letter O, or the half round shape inside English lower case letter E) are separate components needing support in a floated background.
Options included support in the same material color, or support in clear acrylic. If it was clear acrylic, we felt shiny clear acrylic would reflect and cheapen. So we chose non-glare that matched the non-glare surface characteristic of the entire sign background.