Screen Printing 101 @ Leo's Silkscreen Service
As a customer, sometimes you wonder, “HOW DO THEY DO IT?”.
Well, we thought we’d put together a 101 on screen printing to educate our customers.
The technical term for screen printing is “serigraphy”. Screen printing is also known as “silk screening”. It is the process of pressing ink through a fine mesh screen and the screen will allow ink to pass through in certain areas and will block it in others. The screen printing technique was first used by the Chinese nearly thousands of years ago. The Japanese adopted the screen printing process using woven silk to create the mesh. Silk has not been used commonly as they used to, but polyester has been used since the 1940s and is by far the most common type of screen mesh used today.
Let’s go over some basic fundamentals of making a print…
It starts with an idea, then comes artwork. The artwork is then converted into a digital format. Designs are converted dark black before getting outputted onto a film, no matter what color your designs are. Therefore, multiple color designs need to be separated by color and a film positive will be made for each color.
So---The design is then outputted onto a film positive. Film positives are opaque sheets, similar to transparency sheets. The design must be dark enough so that it blocks UV light from the exposure unit to the areas behind the design.
Screens come in different sizes and mesh counts. Mesh is the fabric stretched over the screen’s frame and the mesh count is the tiny holes in it. Understanding what screen mesh to use for particular detail in designs and fabric is important as it determines the amount of ink laid down. We’ll dedicate an entire article in the next few weeks as talking about screens can be another article in itself.
OK---Artwork, design, film output, screens, what’s next? Emulsion. Before the films and screens get burned by the exposure unit (UV light), the screens need to be coated in emulsion and dried. The emulsion is a thick liquid substance which reacts to light.
The emulsion is applied to the screen. Once the screen is coated, the screen is kept in darkness. Any light could start exposing the screen. When you expose the screen to light, since the emulsion is photosensitive, the light causes the emulsion to harden and bind to the screen.
Now, that the film is ready to be burned into the emulsion-coated screen, burning the screen (using UV light), the light exposes the design emulsion, hardening it into the screen everywhere except under the design of the film, which was protected by the light.
After exposing the screen to light, we remove the film and wash out the screen, and we now have our design stencil.
Load The Platen(s)!
Platens are the plates or a flat platform where we lay the shirts on and clamp the screens. This is where we make sure the screen and design will align with the shirt properly.
Let the screen printing begin: Ink is then placed at the top/bottom of the screen, making sure the ink will fill the design stencil. This is process is called “flood stroke”.
Once we’re good to go, holding a squeegee, we pull the squeegee over the design. Lifting up the screen, we check to see if the shirt has a good layer of ink spread evenly. The shirt/fabric is then dried by a flash cure unit. Flash cure units use infrared heat to dry the ink to the touch quickly so that it may receive another layer of the ink or new ink color in multiple color designs.
The print run is done and now you know how screen printing is done!
Of course, there are tons of knowledge absent in this article, but here at Leo’s Silkscreen Service, we hope you know that you are in good hands. We’ve dealt with all sorts of materials and product.
Once upon a time, Leo’s Silkscreen Service was solely a silk screen manufacturer in the Los Angeles area. Now, we are a full-service, creative, screen printing company with no-minimum to mass production capabilities. With our years of experience and knowledge, you get the only the best of the best. Let us know how we can help you. Email us: firstname.lastname@example.org.