[Histonet] vasculature staining in 3D

[M.O.]

Happy Wednesday!

I have an image in my head and I cannot find any image that matches what I
saw - cleared 3D tissue, maybe it was lungs or a heart with blue
vessels/veins stained.

I've done skeletal staining on mouse embryos with alcian blue and alizarin
red and was wondering if there is something similar for soft tissue and
vessels (not fluorescent). Is this something that exists?

I've seen vascular casting, but couldn't find images of cleared tissue with
stained vessels.

Thank you for any hints to my mystery!
-Merissa