Highlighter ink is conveniently used for visualization of blood vessels in chicken embryos. An E3.5 embryo was infused with violet ink, and Z‐stack image with 240 slices of 10 µm each (=2,400 µm) was obtained by macroconfcal microscopy. Vascular networks covering both embryo proper and extraembryonic regions were visualized with a markedly high resolution. See Takase et al ., 792–801.