A screen wash is designed to remove ink from your screen before you remove emulsion. It is to be used in your washout booth and rinsed with water.
A press wash is to be used on press to change ink colors without degrading the emulsion/stencil. Easiway press washes/on press cleaners will evaporate and are not to be rinsed with water. Easiway on press cleaners can be used to clean squeegees, flood bars, presses and other shop tools safely.