What’s the difference between over and under exposure and why is that important?Updated a day ago

Overexposure can cause a loss of image detail because portions of the design become too hardened to wash out. During washout, you'll notice that parts of the image won't open, resulting in missing details in your stencil.

Underexposure can lead to a weak stencil because the emulsion hasn't hardened enough. As you rinse the screen, areas outside of your image may begin to wash away, causing the stencil to break down or lose detail. An underexposed stencil is also less durable during printing and may prematurely deteriorate on press.

The easiest way to determine whether your screen is properly exposed is by using a 21-Step Exposure Calculator.

• If the image stops washing out before step 7, the screen is overexposed.
• If the image continues washing out past step 7, the screen is underexposed.

Using a 21-Step Exposure Calculator helps you dial in the correct exposure time for your specific emulsion, mesh, coating thickness, and exposure unit, resulting in sharper details and a more durable stencil.