When silk screening, only use inks that are designed and optimized for use with the silk screening process. A number of companies, including Speedball, Jacquard and Naz-Dar, manufacture acrylic inks that are made to be used with screen printing. According to Speedball, one acrylic ink manufacturer, their inks offer "the permanence of oil-based inks with the convenience of water wash-up," making them perfect for use with screens that need to be washed for multiple uses.
Some acrylic inks and paints are designed for use on paper, wood and cardboard. Others are designed for use with plastic or metal while others still are designed to be used exclusively with certain types of clothing. Read the label and description of the ink you wish to purchase before purchasing and using it with your silk screen. Inks that are optimized for use with metals will react differently when used with paper. The same rule applies to the other ink types.
Different inks have different drying times. Some inks take as little as a few minutes to dry while others can take several hours. Some inks are also designed to dry faster when placed under direct heat. If you are looking to use the ink on paper or cardboard, you should avoid inks that require heat to dry. Similarly, if you are looking to manipulate the ink in any way after its application, avoid inks that dry too rapidly.
Though many acrylic paints can be cleaned with soap and water, this may not always be desirable. If silk screening a T-shirt or other type of clothing, this type of ink could fade and wear over time as the shirt is regularly washed. Other types of ink that require screen wash solutions or lacquer to clean can provide a longer lasting print, though they may be more difficult to clean up. Again, depending on your situation, this is something you need to take into consideration when buying an ink.