When many people hear, the words “screen printing” or “silk printing” they automatically think of the printing on a t-shirt but screen printing can involve being used on substrates ranging from metal to plastic. Screen printing is best suited for graphic, bold designs. A printing technique is particularly suited for a flat or relative flat surface. The process involves a screen or fine mesh stretched tightly around a frame that is ridge. If there are areas that you do not want printed, they are masked out on the printing screen. To create the print the framed screen will be positioned over the item you want printed with a blob of thick paint. To press the ink through the screen you would use a squeegee. A stiff rubber blade is mounted on a plastic or wooden handle. It is used to pull the pain across the screen to press the ink through the screen.
In the areas that are masked the ink is prevented from passing through but the areas that are unmasked will allow the link to be imprinted. Once this is done, the item is put on a conveyor belt through the heat tunnel. This is called a curing process to ensure that the inks will dry quickly that the material can be packaged or stacked. If the inks have been properly cured, they will remain, even under harsh conditions, on the printed substrate. If there are more colors desired in the final design then the process will be repeated with the different screens. For example, if the design requires three colors then it would require three different screens printed Tshirts.
To make sure that the colors are registered or properly aligned with each other, the screens are normally placed on a rotary press. Some screen printers have fully automatic pressers. With these types, they do not require any manual labor other than setting up the machines and then loading and unloading the machines.
A screen can be masked in many different ways. Applying masking fluid directly onto the screen is the most straightforward way. This way is for simple one or two graphics prints. For printing that is more complex it is ineffective. Screen printers will often use photosensitive emulsions for multicolor jobs. The first step is for the design to create on a clear piece of plastic file. Next, a photosensitive coating is applied to the entire screen surface. Once it has dried, the film will be placed on the screen and then it will be exposed to bright light. After a period of time, the screen printer will wash the exposed areas off the screen with water. Now the screen is ready to print. If you are printing on a dark color, a white base coat will be applied first.