Inks for block printing (relief) & conditioners, oil-based with emulsifier
clean with soap and water.

What is an emulsifier?

An emulsifier is a substance that helps mixing of two substances which are normally not miscible or difficult.
Oil and water repel each other. Oil and water are not miscible. The oil will come to float on the water. Then there is a problem if you want to clean an oil based ink with soap and water. An emulsifier solves that problem. It is added to the oil based ink. Emulsifiers are used much the cosmetics and food industry. An example:
An example of an emulsifier in the food industry is lecithin. Lecithin is in egg yolk, and, for example, is used in the making of mayonnaise. It makes for a good connection between fats and vinegar

Some remarks about ink:

Inks are oil-based, and generally speaking, not hazardous, and they are biodegradable. All inks contain pigments. Through strict legislation is no longer possible to use hazardous pigments.
The devil is in the cleaning, since harmful solvents were used (turpentine, paint thinner, etc.)
As a solution, there are several possibilities:

- Waterbased inks. For example Akua inks. The term "water" is what fashionable. Indian ink is water based. These inks can be fine, but are often still being developed.
- Continue oil-based inks, but with harmless solvents such Geowask K.
- A combination of "both worlds"; Oil-based inks with an emulsifier, such as, for example, Caligo Safewash or Charbonnel Aqua Wash
Steve Hoskins has written an interesting book "Inks". Click here for some interesting reflections by Steve Hoskins