One of the problems I kept facing with my design was pip fragility. The tiny images of dice at the bottom of the Catan pips would often break, and I would then have to throw the whole pip in the trash. The way etching works, the images are composed of very thin walls and columns. Tiny. The size of lead in a mechanical pencil.
So one of the experiments I did was to, before sanding them, apply a generous amount of polyurethane, just using a small paintbrush to put droplets of poly right inside each die image.
This worked ok, but I had to wait overnight before sanding. Other progress I made on the masking methods and in tweaking the design for less fragility and more legibility have made the poly drop treatment unnecessary.