How Screen Printing Works

Have you ever designed or thought about getting custom t-shirt printing done for a gift, promo product or personal use? Chances are the company you dealt with used some form of screen printing to get your artwork onto the garment. It’s a very common method of getting artwork and designs onto t-shirts and other garments that are custom made. Although there are other forms of printing, screen printing is much more versatile than many of these other methods. It has a variety of uses, as well, not just custom t-shirt printing.

Screen printing is a technique that involves a woven mesh that supports a stencil. The stencil forms an open area of mesh that then transfers the ink to the product being printed on. It works especially well for custom t-shirts and garments because of the way the ink is actually transferred onto the cloth. A squeegee is actually then used to force the ink past the threads of the garment. It allows for great durability even when being washed and dried.

Screen printing can also be referred to as “silkscreen printing.” It gained this name because originally a silk mesh was used, but nowadays synthetic threads like polyester are more often used. The entire process first appeared in China between 960 and 1279 AD. Other countries began to adopt the practice soon and were actually able to advance it. It did not find its way to the Western world, however, until the 18^th century. This is likely due to the fact that silk was not widely available until later on in history. It was patented, however, in England during the early part of the 20^th century.

So how does it all work? First, a screen is made from a woven fabric called mesh. This is then stretched out over a frame that is usually made of aluminum or wood. It was human hair that was used as a mesh originally but soon that became silk. More recently however, materials such as nylon and polyester and even steel have been used. Certain areas of this new screen are then blocked off to form a type of stencil. This serves as the image to be printed on the garment. It is a negative of the image so that the ink appears in the open spaces.

Before any actual printing is done, the screen goes to what is called “pre-press.” This is basically a process that cleans up the mesh with the exact shape/image desired to be printed. This is known, now, as the pallet. Tape is then used to protect the pallet from any unwanted leaks from the ink. Then both the screen and the frame are lined with a certain type of tape, depending on the type of ink being used. Lastly, during pre-press, any unwanted holes are blocked so that there are no unintended marks. Again, a special type of tape is used here.

Next, the screen is placed on top of the fabric or garment one intends to print on (i.e. your custom designed t-shirt) and then ink is placed on top of the screen. A “fill bar” or “floodbar” is used to then fill the mesh’s openings with the ink. The bar starts at the back end of the screen and is moved up to the from with a slight downward force. During this, the actual screen is lifted a bit off the garment to avoid contact. A rubber blade (squeegee) is then used to move the mesh down to the garment/printing surface. As the squeegee is then moved to the front of the screen, tension causes the mesh to pull up and away from the printing surface.

Once all of that is done, the ink has been transferred onto the printing surface. And that’s how you custom t-shirt printing is done. However, it is not just used on garments. As mentioned earlier, there are literally thousands of items that utilize or can utilize the screen printing process to transfer images, artwork and graphics onto them. It is a widely used method of creating and decorating products. Even circuit parts can be screen printed on. It really is a useful technique and one of the world’s great inventions.