All About Screen Printing
Screen printing. What is it? Well, as defined by the dictionary, screen print is the force of ink or metal onto (a surface) through a prepared screen of fine material so as to create a picture or pattern. The screen is, basically, a stencil that is then used to apply layers of ink onto the surface. Screen printing is also commonly referred to as silk screening or silk screen printing. A screen printing press allows multiple copies of a design to be printed in an efficient and professional manner. Whether you’re aware of it or not, you’ve probably been a consumer of screen printing if you’ve ever ordered shirts for your kid’s baseball team or for your Wednesday night bowling team.
Now that we know what screen printing is, let’s take a trip down history lane and have a look back at how much the process has changed throughout the years.
The History of Screen Printing and Its Influencers
Screen printing dates back all the way to 960-1279 AD in China during the Song Dynasty. It quickly spread to other Asian countries, such as Japan. It wasn’t until around the late 18th century that screen printing hit its mark in Western Europe. However, since silk mesh wasn’t widely traded in Europe during this time, it took a little more time to gain popularity in Europe.
Andy Warhol, a famed artist (and creator of the Campbell’s Soup can design), is widely credited for popularizing screen printing by using it as an artistic technique. This technique came to be known as serigraphy. Michel Caza, who was an innovator within the screen printing industry, assisted and supported Warhol with his serigraphy ventures.
You’ve probably seen the above image, known as Marilyn Diptych, which is Warhol’s most famed work in which he used a silk screen technique to create an artistic image of Marilyn Monroe.
Corita Kent, a former nun and artist, used bright and colourful serigraphs to bring attention to causes in which she was passionate – such as poverty, racism, war, peace, and social justice. She also designed the 1985 Love stamp for the United States Postal Service, which is shown below.
Arthur Okamura, Robert Rauschenberg, Harry Gottlieb, and Roy Lichtenstein are just a few of the other artists that have used serigraphy as an avenue for artistic expression.
Samuel Simon is said to have had the first patents related to screen printing in 1907. Simon used sheets of cotton and silk, stretched them over wooden frames, and used hand-painted stencils to create the design. John Pilsworth also took a patent for multi-colored screen printing in 1914. Simon and Pilsworth were not the only ones, however, to submit patents during this time. Antoine Vericel submitted one in 2902, Hiram Deeks in 1903, Jehan Raymond in 1906, and Arthur Bostwick in 1907.
Around the time of World War I, commercial screen printing was widely used for printing flags and advertising banners for retail stores. In 1910 Roy Beck, Charles Peter, and Edward Owens introduced the use of photo-reactive chemicals that would create the printing screens. This revolutionized the screen printing process.
In 1960, Michael Vasilantone, who was an artist and entrepreneur, invented a rotatable multicolor garment screen printing machine. He originally used the machine to print logos on team bowling garments and other various fabrics, but later turned his focus to t-shirt printing. In 1967, Vasilantone filed for a patent on his machine and it was granted two years later. The patent was then licensed by numerous manufacturers, which of course resulted in the increased popularity of mass t-shirt printing. So let’s give a big round of applause to Michael Vasilantone who has aided and abetted us in our t-shirt hoarding efforts.
Screen Printing Processes and Techniques
The screen is made out of a piece of mesh that is then stretched over a frame. The mesh itself can be made out of synthetic polymers, such as nylon. The screen is then stretched and attached to a frame, which can be made out of a number of materials such as wood or aluminum. A tensiometer is a tool that can be used to measure the tension of the mesh to make sure it is as tight and secure as it needs to be.
The stencil works as any other stencil you may have used does. The open spaces of the stencil are where the ink will be applied while the rest of the screen is blocked off in the negative area of the image.
The first step of the printing process is considered the “pre-press”. In this step, an emulsion is applied over the screen. In case you’re not sure what “emulsion” is, it is a fine dispersion of minute droplets of one liquid in another in which it is not soluble or miscible.
After the emulsion is applied, the ‘exposure unit’ burns away the unnecessary emulsion, or the negative area of the stencil, leaving behind a clean area in the screen for the desired design.
Next, the pallet, or the surface that is being painted, is covered with a pallet tape. The tape prevents any unwanted ink from leaking through the screen or transferring onto the surface. Then, the screen and frame are also lined with tape. The type of tape that is chosen depends on the type of ink being used. UV and water-based inks usually require more aggressive tapes.
Finally, the last step of the pre-press process is to block out any pinholes that may be present in the emulsion. To do so, you can use tape, block-out pens, or a specialty emulsion. If this step is skipped and any pinholes are present, the ink will seep through to the pallet and create unwanted marks.
For the next step, the ink is poured on top of the screen and then a fill bar is used to push the ink through the holes in the mesh. The screen is lifted slightly to prevent contact and then, starting at the rear of the screen, pressure is applied to the fill bar and is pulled down in order to push the ink towards the front of the screen. This action causes the mesh screen to be filled with the ink. Then, a rubber blade is used to press the screen down to the pallet and simultaneously pushed back towards the rear of the screen. The tension from the rubber blade causes the mesh to be pulled up and away from the surface of the pallet, leaving the ink on said surface.
If your design calls for multiple colors, a wet on wet technique is often used. This technique allows colors to dry while on the screen press. If not using the wet on wet technique, the item, after being readjusted on the press, dries in between colors and is then printed with a different color using a different screen.
In some cases, the screens will have to go through a de-hazing process. De-hazing will remove any “ghost image” that is left behind from the emulsion mixture. Ghost images often occur around the outline area of previous stencils used, due to ink being trapped in the mesh.
Another technique that can be used is the photo emulsion method. With photo emulsion, the original design is placed on a transparent overlay either through painting, being photocopied, or being printed on the overlay. As with the other methods, the negative areas (or the area not to be printed) are not transparent. The film used is any material that can block ultra violet light, such as card stock. After choosing the screen, it is coated with an emulsion mixture, dried, and then “burned”. Once that is complete, the overlay is placed on top of the screen and is exposed with an ultra violet light source. The design should then have been transferred to the surface.
Screen printing is not only for t-shirts or other articles of clothing. It is also used on items such as clocks, balloons, decals, medical devices, electronics, product labels, signs, and so much more.
Screen Printing Materials and Effects
- Caviar beads are small, soft beads that can be applied to a surface (usually best used on solid, flat areas) to create an interesting and eye-catching texture. In order to apply caviar beads, an adhesive is applied directly to the desired surface in the shape of the preferred design, with the beads being applied on top of the adhesive.
- Cracking ink creates an effect in which the ink produces an intentional cracked surface after it has dried.
- Discharge ink is used to apply lighter colors onto a darker surface by removing the dye that is present on the garment. However, the end result of the colors can be more difficult to control using this effect.
Expanding Ink (Puff)
- Puff is an additive to plastisol ink which will raise the print off of the surface, giving it a 3D look and feel.
- Flocking creates a velvety texture by applying the flocking material to an adhesive.
- Foil creates a reflective/mirror look. The adhesive is applied through the screen printing process and the foil is then applied through a heat press process.
Four-color Process (CMYK Color Model)
- In the four color process, the design is created and then separated into four colors (Cyan, Magenta, Yellow, and Key (black)) that, when combined, can create a full spectrum of colors. Because only four screens are used, costs, time, and set-up are all reduced. Below is a depiction of the effects of combining the four colors.
Glitter or Shimmer
- Metallic flakes are added to the ink base in order to create a sparkling effect.
- A clear based is applied over an already printed ink to create a glossy effect.
- Similar to glitter or shimmer, even smaller particles are added to the ink base to create a metallic effect.
- Using a solvent-based ink, the result is a highly reflective silver print.
- Nylobond is a special ink additive that allows for printing on waterproof or technical fabrics.
- Plastisol is the most common ink used for garment printing. Plastisol gives off good color and clear details with a slightly “plastic” feel. The texture can become softer by adding special additives. Heat is required for many plastisol inks in order to cure the print.
PVC and Phthalate Free
- A relatively new type of ink, PVC and Phthalate Free has similar benefits of plastisol, but without the two main toxic components. The texture is also softer than plastisol.
- Suede ink is an additive of a milky color that is added to plastisol. By using this additive, any plastisol color is given a suede feel. The agent used for suede ink is actually similar to the puff ink agent, except it does not bubble as much.
- Water-based inks can penetrate fabric more than plastisol and are softer to the touch than plastisol, as well. Water-based inks are ideal for printing dark inks on lighter garments and are also useful when printing on larger areas where texture is important.
- High build creates a Braille effect. To achieve this, a varnish is used against a lower mesh count and with either many coats of emulsion or a thicker grade of emulsion. Once the varnish is applied to the surface, a “raised” area is created, giving you the Braille effect.
Now that you’ve had your history lesson for the day, hopefully now you have a better grasp of what screen printing, where it began, and the options available to you for all of your business or personal needs.
If you’d like more information on screen printing or have order inquiries, contact US Logo at (316) 264-1321 to speak with a member our friendly staff!