Cranfield's Caligo Ink is a line of Safe Wash Etching ink for artist quality results in a non-toxic environment. Though oil-based, it can be cleaned up with just liquid soap and water. This Extender is an ink just like all the colors in the range, just made with a transparent pigment. Add to ink to increase transparency and reduce the strength. This is a 250gm tin of Caligo Safe Wash Etching Ink Extender. Made in the UK.