To obtain an ink dissolution liquid which can remove ink adhered to an ink container or a printer safely in a simple manner and can be separated from ink and reused after the removal treatment by mixing a crude citrus oil with water and a specified amt. of an additive at least contg. coconut oil and a fatty acid.

A crude citrus oil 2, such as so-called orange oil extracted from the skin of citrus fruits, is mixed with about 1-20 times as much water 3 and 0.01-0.2 times as much additive 6 at least contg. coconut oil and a fatty acid 6. In another way, the crude oil 2 is mixed with about 1-10 times as much water 3 and 0.01-0.2 times as much additive 6 at least contg. an alcohol 4. In still another way, the crude oil 2 is mixed with about 1-10 times as much water 3 and 0.02-2 times as much additive 6 at least contg. an alcohol 4, coconut oil, and a fatty acid 5. Those ingredients are mixed under stirring to give a cloudy liquid.