Dr. Ph. Martin’s Bleed Proof White is arguably the most popular white calligraphy ink on the market; many calligraphers love it and use it often. Dense, opaque watercolour, gives good coverage. Can be thinned with water. When diluted, will produce fine hairlines for Copperplate and Spencerian.
Sold in a wide necked bottle for easier access when using an angled pen holder.
For more Dr. Ph. Martin's inks: https://www.stickerrificstore.com/dr-ph-martins