Stained Glass Inspired Porcelain Shallow Bowl by JillyBeanPottery - interesting technique - could be done with raised glazed application for the "lead" lines on greenware with panel glaze application after first firing.
Check out info on resin casting. You have a mold, mix the resin with a catalyst. Whatever is in the mold gets embedded in plastic. - This link doesn't include info, but it's a reminder to go check out more info on resin casting