That is a good thought, but having the torpedo etched is not possible for a couple of reasons. First, not so much a technical constraint as aesthetic, is that the point was to have raised detail on the token since it's easier for light to catch the edges on raise details than sunken. Technically though, making the relief sunken isn't going to save any material. I've actually hollowed out the entire underside of the base on the side with the missile relief to the very minimum wall thickness (you can sort of see this on the zoomed in view of the unpainted FUD). This was both to save cost and to allow the markers to stack flat with the relief fitting inside the base of the marker on top. To make the relief sunken rather than raised means that I'll have to fill in the underside and remove the material from the top which comes out to less material removed because the shape of the missile on the marker is less area than the rectangle I'm filling in to maintain the minimum wall thickness.
Basically where the problem comes in is this: The minimum wall thickness for the black and white detail materials is 1mm. That means I have to have at least 1mm of material under the bottom of the tray side and on top of the hollowed out section on the left or shapeways won't print them. In order to get that without killing the ability to actually hold the dice, I had to make the base 2.5mm thick.
Now, the other option was to build them only to print in the White Strong and Flexible and FUD materials. That reduces the tolerance to .7mm as the minumum wall thickness and means that I'm able to make the marker 2mm thick. In other words, to have the option for the Detail materials which are far better quality prints, I had to add .5mm of material to each marker. The end result being that 15 markers are around $26USD while 18 of the thinner markers are $25USD.
What this leaves for options is to attempt to save material somewhere else on the model and right now the only somewhere that hasn't been tweaked are the edges of the marker. I'm looking at adding a beveled edge around the outside which should save a bit of material compounded by each marker for what I hope will be significant savings. I'm also looking at making greater contrast in the levels on the relief to help fix some of the issues with the WSF material too which may make the option for the better materials less necessary especially if I can get it to 20 markers for 25USD which is the minimum dollar value for an order on shapeways.
