After you have a frame with mesh inside of it, you will need to prep it with a coat of emulsion. This is actually quite easy to do. You simply need to abrade the mesh surface with a mild abrasive as you clean the mesh to ensure that there is no grease or dirt on it. Usually this is done with a washout booth where you will be able to easily soap the screen with “mesh prep” then thoroughly rinse it off once again. Of course, you will also need to have a dust free environment where you can allow them to completely dry after you do this. Only then will you know that the screen is clean enough to receive the emulsion without you having to deal with any complications.
Coating The Screen With Emulsion
Now your screen is ready to be coated with emulsion, which is a light sensitive liquid chemical. It is the most light sensitive once it is dry. The best tool to use for this process is a scoop coater even if you are doing this at home. This tool was created to resemble a trough that is the width of your screen with one rounded, smooth edge. So, if you are dealing with a 20 x 24 screen the scoop coater would be approximately 14 inches wide so that you are able to coat the length of the screen with just one pass from the top to the bottom.
This will provide you with the most consistent, smoothest coat while ensuring that the thickness is even. You will find that this is important since the stencil’s thickness is directly related to the amount of ink that you deposit on the shirt. What this means is that the thicker the emulsion is, the deeper the stencil is and the more room your ink will have for being deposited upon the shirt so that it has better “coverage.”
What Type Of Emulsion To Use
You should use either subdued yellow or red light to coat your screens with. This is something that you will want to do in a “dark” or “exposing room.” Of course, your exposure table should also be located here. This is quite handy as the screens dry too because then they will need to be handled in the same lighting conditions.
Creating A Thicker Layer Of Emulsion
Whenever you need to create a thicker layer of emulsion on the substrate side (the side of the shirt that comes into contact with the screen where you want the stencil’s thickness to be present) you will need to make sure that you coat that side first. This coating should pass lengthwise from top to bottom. You will then want to put at least one more coat on the shirt from the inkwell side (the side where the ink is place and pushed through the screen with your squeegee). In doing so you will be able to push a lot of the emulsion to the substrate side, making it look as though it is very glossy or has a wet sheen.
Once you have done this you can dry the screen on a level rack with the substrate side facing downwards. In this way gravity will be able to ensure that the emulsion remains the thickest on your substrate side. Just make sure that the drying rack is located in a light safe room, is level and allows for plenty of circulation. Otherwise both your emulsion and your screen will get messed up. Now it is just a matter of finishing the printing process and then you will have a screen printed shirt that you will be proud of.