The Process of Screen Printing
Screen printing, likewise called silk screening, is a method to print customized or personalized logos, text, or art work on t-shirts, sweatshirts, koozies, bags or any other apparel you want to customize.
Essentially, a screen is imprinted with your design, positioned over the item to be printed, and then ink is required through the screen with a squeegee onto the product. The product is then placed through an oven to treat the ink.
Screen Printing Process
We decided to describe the procedure of screen printing to help you comprehend the actions it takes to create your customized screen printed t-shirts.
Step 1: Artwork
The artwork is either sent to us from our customers or we create it from the customer’s idea. We choose to utilize or create vector type files since it provides great sharp images no mater what size is used.
Once we have the artwork, we create t-shirt composites, that we place on our website, for the customer to evaluate and approve. This is not an actual printed t-shirt but a computer system generated t-shirt, which will be a really great representation of what the artwork will look like and shows positioning of the art work.
The customer needs to approve this t-shirt composite prior to going to the next step. At this time you can advise to make any changes. We’ll help you till you are 100% satisfied with the design!
Once the art work is authorized we print the design as a positive on a transparency. If the style has more than one color, we have to separate the design and print a positive for each color so that we can develop a different screen for each one.
Step 2: Screen Preparation
The screens that we use are installed on a metal frame and there are various screen mesh sizes. The mesh size to use is determined by the detail of the artwork. The more fine line detail, the greater the mesh count screen is required.
The screen needs to be prepped by cleaning with a screen wash and after that with a degreaser. The screen is then dried.
When the screen is dried it has to be covered with a photosensitive emulsion. This needs to be used under yellow light because any direct exposure to UV light will trigger the emulsion and render it ineffective. The screen is positioned in a dark drying cabinet so the emulsion can dry.
Step 3: Screen Exposure
Once the emulsion has dried, the positive film transparency is momentarily taped to the back of the screen. It is positioned according to how it will appear on the t-shirt.
Then the screen is placed into the exposure unit. The direct exposure unit shines UV light on the screen, which exposes the photosensitive emulsion that is not being blocked by the art work on the transparency.
Once exposed, the screen is positioned in the wash-out tub and the screen is sprayed with high pressure water. The emulsion that was blocked out by the artwork washes away with water.
The emulsion that was exposed to the UV light is now chemically bonded to the screen and does not rinse with water. So after spraying the screen, the only openings on the screen, is the art work image.
If there is more than one color you do this for each screen.
Step 4: Printing The Artwork Onto The T-Shirt
After the screen dries, the screen must be blocked by taping the border of the screen and any undesirable openings. Pinholes are completed utilizing a block-out pen. This procedure is repeated for all screens.
The screen is then put on the press. There are numerous types and sizes of presses; we use a 4-platen 6-color manual press. This means we do printing designs with 6 colors and the ink is applied by hand.
The screen is clamped in the press and aligned so that the image will print correctly onto the t-shirt. If there is more than one color then there is a screen for each color and they need to be placed on the press and each one is lined up with the other screen so that when the ink is used, each color remains in the correct position.
The positioning is done with registration marks and a careful eye. Once the screen or screens are on press, now it’s time to apply the ink. The ink is plastisol ink and the specific color of ink is spread along the base of the screen or screens. A squeegee is utilized to use the ink.
The t-shirt is placed on the platen. The screen is put into position above the platen. To use the ink, we initially need to flood the screen with the ink by pulling a thin coat of ink throughout the top of the screen with the squeegee. The screen is then lowered down over the t-shirt.
We use the squeegee to push the ink through the screen onto the t-shirt. The press is designed so that the screen is constantly in alignment with the platen, therefore you can be sure the screen is always in the exact same position. So if you are doing more than one color, the t-shirt remains on the platen, the next screen is turned over on the platen and the new ink color is applied to the t-shirt.
This procedure is repeated for each color of the design. In some cases, in order to print one color on top of another color, it might be required to flash the previous ink on the tee shirt. To flash, the platen is turned under the flash system, which is a heater the size of the platen. The flash system will heat the ink extremely quickly, in a matter of a few seconds, so that it gels over, which enable you to print the next ink directly over top.
This is important especially when doing an underbase that all other ink colors are printed straight on. When all colors have been used, the t-shirt is removed from the platen and placed on the conveyor dryer oven.
Plastisol type ink only cures with heat, so the t-shirt needs to be heated to a minimum of 300 °F to set the ink. The t- shirt is finished when it comes out of the oven, unless there is another design being printed on the opposite side and/ or sleeve, then the screen printing process is repeated.
This process is the same for printing on tee shirts, sweatshirts, fleece wear, koozies, bags or other garments.
revelshore.com provides a wide variety on screen printed garments. Call (832) 464-8008 today for a quote and find out how much we can do for you.