These are all replica vintage inks that exhibit classic period ink behaviours with mild (when compared to our modern bulletproof and eternal inks) water resistance upon the page (particularly after the passage of time, a week or so or more upon the page will increase the ability to resist water).
Please bear in mind these are classic style inks and will NOT exhibit the same durability of the more modern Noodler's Eternal and Bulletproof lines. It will not resist the UV rays from the sun nor many of the chemical tools of the forger.
However, at the time, the inks would have most certainly been classed as being "permanent" by the industry of ink manufacturers.
We use a couple of these inks ourselves the bright turquoise shade of blue of Midway Blue and the bright purple of North African Violet.
All of the V-Mail inks are in the GLASS 3oz bottles, this is around 90ml in Euros.