This marker was made specifically for a challenge in Privateer Press's "Halfaug" season for Warmachine/Hordes, but it can serve equally well as an objective marker for any 28mm scale game where a creepy cave/sorcerer's home/skull thing can be useful. Printing at .3mm will give you noticeable enough layers that a dark wash will bring them out and make the skull appear to be made of shale. Printing at .1mm will give you a smooth looking skull and superior crystals on either side.