Not critical

Dear Gary,

Have been using "Oil Wash" (1tsp Black "India"/Drawing Ink + 345ml "IsoCol" Isopropyl rubbing alcohol) for raw washes, wood staining, weathering, and as the base thinner for Tamiya "XF-series" acrylic washes for years. When I need more ink, it's straight to the newsagents for whatever cheapest "black drawing ink" they have available...

Honestly, I've never looked more closely at the bottle pre-purchase than that, and have yet to have a "failure".

Of course, you'll likely be sealing the model with Dullcote or similar, so "permanency" of the ink is mitigated by the sealant coat...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS given the "permanency" of "Oil Wash" if you spill it on a wood workbench, or on clothing, I'd suggest that either option will be "permanent enough" for most modelling missions...

Been using them for years

I'm on the road at the moment so I don't know which I have, but suspect it doesn't make a difference.  I dilute mine 1 Tablespoon to 1 pint 91% isopropyl and get a lean mix that makes a good foundation and it dries quick.  The 91% also fades the paint a tad.

I use 70% isopropyl alcohol

I use 70% isopropyl alcohol and one or two teaspoons of black india ink per bottle. The 91% strength is a little dangerous to use because it will soften most plastic materials.

I also prefer the 70% variety

I also prefer the 70% variety for washes, as 90% and higher can lift paint (I often use it to strip old paint in preparation for a new look) and it makes me nervous to put that on an almost finished model.

India Ink

Hi all,

         I make two types of black washes.One with a teaspoon of India Ink and one with 2 and both with 90% Iso,if this  strength is attacking plastic/lettering,....well, there is something wrong,very wrong.

Best,Dr Dirt