When preparing your screen for printing there are important steps to follow to ensure the process will go smoothly without problems or difficulties. After your screen is coated with emulsion, dry to the touch and ready for exposure, the printed artwork/ film should be laid out face down on to the face side of the screen. The film should be secured to the screen using transparent tape (scotch tape works best) so it doesn’t interfere with the exposing process. Be sure the image is attached in desired print position so that it reads reversed on face side and reads correctly when viewing through the well side. Put the screen face down in the exposure unit and use corresponding exposure time based on the mesh count. After the screen has been exposed, it is ready to wash out. Begin soaking the screen with low pressure until the stenciled area slowly becomes visible. Then, concentrate on washing out the loose emulsion using medium to high pressure until image becomes visible in the screen. You should be able to see light through the open areas as the emulsion washes out. Once you can clearly see the mesh through these areas, you’ll know that the ink will pass through, as well. It’s a good practice in making sure that your screen has been fully washed out by holding it up to a light source and checking for any blockage.
You might notice some light passing through areas in the screen that are supposed to be blocked. We refer to these areas as “pin holes”. It’s important to cover up pin holes as they will let ink pass through unwanted areas in the screen. There are two ways to go about covering pin holes depending on the severity. If you experience several holes close to the artwork, or the surrounding area, you can use a small paint brush and dab emulsion over the holes on the face side of the screen. After you cover the holes, you can expose the screen again or let it sit out in direct sunlight for a few minutes. If there are only a few, you can cover them using small pieces of tape. If you use the tape method you must be careful when cleaning or wiping the screen face during printing as you can remove or shift the tape.
Another necessary step in the pre-print process is taping up the open areas on the outer parts of the screen where emulsion didn’t cover. There is a product called split tape designed specifically for this purpose. It’s called split tape because half of the tape is less adhesive than the other and is designed for going on the well side of the screen. The less adhesive half is made for sticking to the frame and the more adhesive half is made for sticking directly to the screen. If you don’t have split tape you can block these areas by applying masking tape or packing tape to the face side of the screen. It’s recommended to tape the face side of the screen because other tapes can lift inside of the well and breakdown over time due to numerous factors including squeegee movement, cleaning agents, and ink moisture that may result in having to reset and tape it all over again.
If you want to take an extra step to increase the longevity of your emulsion’s performance, it’s recommended to use a product called Hardener X. After screen is fully dry, spray both sides of the screen and, using a clean cloth or paper towel, even out the application throughout the whole screen (it’s recommended to do this process twice). It is really important the screen is completely dry and free from loose emulsion before applying hardener as it will create a thin film that will prevent ink from passing through the open areas of the screen.