How do I figure out exposure times?
Figuring out exposure times is one of the most difficult tasks in screen printing. The best thing you can do is invest in a 21-Step Exposure Calculator.
How does it work? It's pretty simple. Place the calculator on the screen, away from the design. Expose the screen.
Wondering how to even pick a time to start? If you're using a Baselayr emulsion, each page shares a starting time depending on the exposure unit you're using. Remember, it's a starting point. Depending on the other factors mentioned before, you will have to adjust the time to find the perfect time for exposing that particular screen.
Once the screen has been exposed, bring it to the washout booth. Soak the screen in water in a dip tank or gently rinse it with a hose and let the water soak into it before using a pressure washer. Rinse the screen, and take a look at the calculator.
The lucky number you want to hit is seven. If you've hit the seventh mark, it means you're screen is perfectly exposed! If you can wash out past the seventh mark, the screen is under-exposed. If it stops washing out before the seventh mark, the screen is over-exposed.
Off by a few steps? No worries. The exposure calculator has a handy table that shares how you should adjust your time based off what step you had reached. Grab a new screen, make the time adjustments, expose, and bring it back to the washout booth.