I have done some experimenting with "Future Floor Finish" as a thinning agent/ carrier for both ink and acrylic paint washes.
Future Floor Finish is available at your local supermarket here in the USA for about $6.00 USD for 27 fluid ounces. It is a pure clear acrylic so it makes a very strong wash, and it acts as a surface tension remover to allow the wash to really settle into all those little details. It also has a pleasant fruity odor.
I thin it and then experiment until I get the exact wash shade I desire and store the particular wash mix in 1 pint canning jars with label.
The future floor wax also works beautifully as a gloss clear protective coat when applied by itself. You clean your brushes with soap and water, just the same as for any acrylic paint.
Once dry, over night, spray with a matt artists finish and you have a good looking, well protected painted figure.
Actually experimenting with dipping figures in this type mixture at the moment, because you can achieve virtually any color of wash to any intensity you desire.
Once dry you can then drybrush or use any other painting process you desire for effect with the darker wash in the recesses. I have been able to really speed up the painting of rank and file with this technique. Without the objectionable side effects of the normal dipping iprocess involving wood finishes. With this process I have full control of color, hue, intensity etc. by simply experimenting, anyone can do the same.
If your local store does not have "Future Floor Finish" (It is a liquid acrylic product by SC Johnson Company) look for a similar product that is available to you locally.
I hope this is of interest to some, and stirs some creative juices in all.