For shadows that don’t turn your heart into a paperweight, keep the resin just thick enough to hold its shape but thin enough to let light slip through the veins. Layer a thin, clear coat first, then paint a dark base—think midnight ink—on the veins, and seal with a second clear coat. The key is to let the darker pigment sit in a shallow trench; the resin above will be almost translucent, letting the shadows bleed without cracking. Also, cure at a slow, steady temperature so you don’t get those brittle, “crazed” veins. Trust me, a little patience and a lot of careful sanding keeps the darkness alive without the fragility.